WO2025103239A1 - 电化学装置及用电设备 - Google Patents

电化学装置及用电设备 Download PDF

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Publication number
WO2025103239A1
WO2025103239A1 PCT/CN2024/131037 CN2024131037W WO2025103239A1 WO 2025103239 A1 WO2025103239 A1 WO 2025103239A1 CN 2024131037 W CN2024131037 W CN 2024131037W WO 2025103239 A1 WO2025103239 A1 WO 2025103239A1
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WIPO (PCT)
Prior art keywords
electrochemical device
pressure relief
metal sheet
shell
hole
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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PCT/CN2024/131037
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English (en)
French (fr)
Inventor
张国文
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Ningde Amperex Technology Ltd
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Ningde Amperex Technology Ltd
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Publication of WO2025103239A1 publication Critical patent/WO2025103239A1/zh
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    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/30Arrangements for facilitating escape of gases
    • H01M50/317Re-sealable arrangements
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10Primary casings; Jackets or wrappings
    • H01M50/102Primary casings; Jackets or wrappings characterised by their shape or physical structure
    • H01M50/103Primary casings; Jackets or wrappings characterised by their shape or physical structure prismatic or rectangular
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10Energy storage using batteries

Definitions

  • the present application relates to the field of battery technology, and in particular to an electrochemical device and electrical equipment.
  • the shell of the electrochemical device is provided with a notch groove, which can rupture when the internal pressure of the electrochemical device is too high to form a pressure relief channel to relieve the pressure of the electrochemical device.
  • the thermal sensitivity of the notch groove is poor, resulting in poor reliability of pressure relief and a high probability of thermal runaway.
  • the present application provides an electrochemical device and electrical equipment, which can effectively improve the pressure release sensitivity of the electrochemical device.
  • an electrochemical device comprising:
  • the housing comprises a first wall body and a second wall body, wherein the first wall body is provided with a first through hole;
  • a pressure relief mechanism covering the first through hole, the pressure relief mechanism comprising an adhesive film, the adhesive film being capable of melting or losing adhesion under heat to form a first pressure relief channel communicating the inside and outside of the housing;
  • the second wall is provided with a notch groove, and the notch groove can be broken when the internal pressure of the shell reaches a threshold value to form a second pressure relief channel connecting the inside and the outside of the shell;
  • the depth of the notch groove is S1, and the thickness of the second wall is S2, satisfying 0.1*S2 ⁇ S1 ⁇ 0.95*S2.
  • the electrochemical device includes a shell and a pressure relief mechanism
  • the shell includes a first wall and a second wall
  • the pressure relief mechanism covers the first through hole of the first wall
  • the pressure relief mechanism includes a film
  • the film can be melted or debonded by heat to form a first pressure relief channel connecting the inside and outside of the shell
  • the shell is also provided with a notch groove
  • the notch groove can be broken when the internal pressure of the shell reaches a threshold value to form a second pressure relief channel connecting the inside and outside of the shell, that is, when the temperature of the electrochemical device is high, the first pressure relief channel can be formed, and when the internal pressure of the electrochemical device is high, the second pressure relief channel can be formed, so that the electrochemical device can form two pressure relief channels.
  • the pressure relief mechanism can effectively sense the heat generation of the electrochemical device and produce pressure relief when the melting point is reached.
  • the electrochemical device produces less heat and more gas, such as over-discharge, the electrochemical device produces less heat and more gas, so pressure relief is required.
  • the pressure relief mechanism is sensitive to temperature, which may result in failure to release pressure in time.
  • the notched groove can effectively sense the gas production of the electrochemical device. When the gas production reaches a certain level, the outer shell expands and deforms, and the notched groove opens.
  • the notched groove can be easily broken when the pressure inside the shell is large, the pressure relief reliability is high, and the cost of the notched groove is low, and the notched groove is not easy to break when the electrochemical device falls or is subjected to external force; when the notched groove is deep, the pressure relief response is fast, but too deep is easy to cause rupture, and when the notched groove is shallow, it is not easy to break, but the pressure relief response is slow; through the above technical scheme, limiting the depth of the notched groove can balance the relationship between the two, and because the present scheme is the joint action of the pressure relief mechanism and the notched groove, the depth of the notched groove can be made smaller without the problem of slow pressure relief response; if only a single notched groove pressure relief function is set in the electrochemical device, because the pressure relief sensitivity of the notched groove is low, the notched groove needs to be deepened, but when the notched
  • the notched groove can be further made to rupture easily when the pressure inside the shell is high, and the pressure relief reliability is high.
  • the cost of the notched groove is low, and the notched groove is not easy to rupture when the electrochemical device falls or is subjected to external force.
  • the depth S1 of the notched groove and the thickness S2 of the second wall satisfy 0.55*S2 ⁇ S1 ⁇ 0.8*S2, it can be further made that when the pressure inside the shell is large, the notched groove is easy to rupture, the pressure relief reliability is high, and the cost of the notched groove is low.
  • the notched groove is not easy to rupture when the electrochemical device falls or is subjected to external force.
  • the pressure relief mechanism further includes a first metal sheet, and the first metal sheet is disposed on a side of the adhesive film facing away from the housing.
  • the water seepage area of the adhesive film can be reduced, so that the sealing effect of the pressure relief mechanism is better.
  • the first metal sheet is arranged in a circular shape
  • the adhesive film is arranged in a circular or annular shape
  • the first through hole is arranged in a circular shape
  • the diameter of the first metal sheet is less than or equal to the outer diameter of the adhesive film
  • the diameter of the first metal sheet is greater than or equal to the diameter of the first through hole.
  • the first metal sheet by setting the first metal sheet into a circle, setting the adhesive film into a circle or an annular shape, setting the first through hole into a circle, and making the diameter of the first metal sheet less than or equal to the outer diameter of the adhesive film, and making the diameter of the first metal sheet greater than or equal to the diameter of the first through hole, it is possible to facilitate the assembly of the adhesive film, the first metal sheet and the outer shell, and the first metal sheet can cover the first through hole, thereby reducing the possibility of water vapor penetrating into the interior of the outer shell through the adhesive film and the first through hole, so that the sealing effect of the pressure relief mechanism is better.
  • the pressure relief mechanism further includes a second metal sheet, the second metal sheet is disposed between the adhesive film and the shell, the second metal sheet is welded to the shell, and the second metal sheet is provided with a second through hole.
  • the connection between the pressure relief mechanism and the outer shell can be made more stable and the sealing effect can be better.
  • the first metal sheet is arranged in a circular shape
  • the first through hole is arranged in a circular shape
  • the second metal sheet is arranged in a circular ring shape
  • the outer diameter of the second metal sheet is greater than or equal to the diameter of the first through hole
  • the diameter of the first metal sheet is less than or equal to the outer diameter of the second metal sheet
  • the diameter of the first metal sheet is greater than or equal to the inner diameter of the second metal sheet.
  • the diameter of the first metal sheet is less than or equal to the outer diameter of the second metal sheet, which can reduce the possibility of the first metal sheet blocking the welding of the second metal sheet to the outer shell; the diameter of the first metal sheet is greater than or equal to the inner diameter of the second metal sheet, so that the first metal sheet can cover the second through hole, reducing the possibility of water vapor penetrating into the interior of the outer shell through the adhesive film and the second through hole, so that the sealing effect of the pressure relief mechanism is better.
  • the first through hole is arranged in a circular shape, the diameter of the first through hole is D1, the second metal sheet is arranged in a circular ring shape, the outer diameter of the second metal sheet is D2, and the inner diameter of the second metal sheet is D3, satisfying 0.2mm ⁇ D1 ⁇ 5mm, 1mm ⁇ D2 ⁇ 6mm, and 0.1mm ⁇ D3 ⁇ 3mm.
  • the first through hole can provide a first pressure relief channel with a larger cross-sectional area when the electrochemical device is in thermal runaway, and there is no need for a larger-sized pressure relief mechanism to cover the first through hole, which facilitates the installation of the pressure relief mechanism;
  • the outer diameter D2 of the second metal sheet is 1mm to 6mm, the second metal sheet has enough area to fit with the outer shell, which facilitates the welding of the second metal sheet and the outer shell, and the second metal sheet will not extend beyond the outer shell, which has a low cost;
  • the inner diameter D3 of the second metal sheet to 0.1mm to 3mm, when the first pressure relief channel is formed through the second through hole, the second through hole can provide a first pressure relief channel with a larger cross-sectional area, and there is no need for a larger-sized adhesive film and the first metal sheet to cover the second through hole, which facilitates the installation of the adhesive film and the first metal sheet.
  • the thickness of the first metal sheet is H1
  • the thickness of the second metal sheet is H2, satisfying 0.03 mm ⁇ H1 ⁇ 1 mm, and 0.03 mm ⁇ H2 ⁇ 1 mm.
  • the sealing effect of the first metal sheet and the second metal sheet is better, reducing the possibility of water vapor penetrating into the interior of the shell, and the thickness of the pressure relief mechanism can be smaller, so that the pressure relief mechanism occupies less space in the length direction of the electrochemical device, which is beneficial to improving the energy density of the electrochemical device.
  • the melting point of the adhesive film is T, satisfying 95°C ⁇ T ⁇ 135°C.
  • the sealing reliability of the adhesive film to the first through hole can be made higher, and when the electrochemical device is in thermal runaway, the adhesive film can melt or lose adhesion to form a first pressure relief channel, so that the pressure relief sensitivity of the electrochemical device is higher.
  • the adhesive film includes a first adhesive layer and a second adhesive layer, wherein the first adhesive layer and the second adhesive layer The two adhesive layers are stacked, the second adhesive layer is located on the side of the first adhesive layer facing away from the housing, and the melting point of the first adhesive layer is lower than the melting point of the second adhesive layer.
  • the first adhesive layer can melt to fit with the shell, and the second adhesive layer will not melt, so as to avoid the adhesive film from over-melting and affecting the installation of the adhesive film, and also reduce the amount of adhesive overflow of the adhesive film.
  • the melting point of the first adhesive layer is T1
  • the melting point of the second adhesive layer is T2
  • 95°C ⁇ T1 ⁇ 135°C, 140°C ⁇ T2 ⁇ 190°C are satisfied.
  • the sealing reliability of the adhesive film to the first through hole can be higher, and the first adhesive layer can melt before the second adhesive layer, so that it is convenient to install it on the housing when the adhesive film is activated at high temperature; when the electrochemical device is in thermal runaway, the first adhesive layer can melt or lose adhesion before the second adhesive layer to form a first pressure relief channel, so that the pressure relief sensitivity of the electrochemical device is higher and the amount of adhesive overflow of the adhesive film can be reduced.
  • the pressure relief mechanism also includes a first metal sheet, which is arranged on the side of the adhesive film facing away from the shell, and the adhesive film also includes a third adhesive layer, which is located between the second adhesive layer and the first metal sheet, and the melting point of the third adhesive layer is lower than the melting point of the second adhesive layer.
  • the third adhesive layer can melt to adhere to the first metal sheet, while the second adhesive layer will not melt, so as to avoid excessive melting of the adhesive film and affect the installation of the first metal sheet, and also reduce the amount of adhesive overflow; when the electrochemical device is in thermal runaway, the first adhesive layer and the shell, and the third adhesive layer and the first metal sheet can melt or lose adhesion to form a first pressure relief channel, thereby improving the pressure relief sensitivity and reliability of the electrochemical device and reducing the probability of thermal runaway of the electrochemical device.
  • the melting point of the third adhesive layer is T3, satisfying 95°C ⁇ T3 ⁇ 135°C.
  • the sealing reliability of the adhesive film to the first through hole can be higher, and the third adhesive layer can melt or lose adhesion before the second adhesive layer, so that it is convenient to install it on the first metal sheet when the adhesive film is activated at high temperature; when the electrochemical device is in thermal runaway, the third adhesive layer can melt or lose adhesion before the second adhesive layer to form a first pressure relief channel, so that the pressure relief sensitivity of the electrochemical device is higher.
  • the housing is provided with a groove, the first through hole passes through the groove, and the pressure relief mechanism is accommodated in the groove.
  • a groove is provided in the outer shell, and the first through hole passes through the groove, and the pressure relief mechanism is accommodated in the groove, so that the thickness of the part of the pressure relief mechanism that exceeds the outer surface of the outer shell is smaller, or the pressure relief mechanism does not exceed the outer surface of the outer shell, thereby reducing the possibility of the pressure relief mechanism interfering with other components and being damaged or detaching from the outer shell.
  • the first through hole is arranged in a racetrack shape, a rectangle or an ellipse shape.
  • the first through hole in a racetrack shape, a rectangle or an ellipse, when the thickness of the electrochemical device is small, the area of the first through hole is large and the pressure relief reliability is high.
  • the outer shell includes a shell and a shell cover
  • the shell includes a bottom wall and a plurality of side walls surrounding the bottom wall, the bottom wall and the plurality of side walls together form a accommodating space with an opening, the shell cover closes the opening, the side wall is the first wall body, and the bottom wall or the shell cover is the second wall body.
  • the electrochemical device further includes a pole, and the pole and the first through hole are disposed on the same side wall.
  • a spacing space is formed between the electrode assembly and the outer shell on the side where the electrode is arranged in the electrochemical device.
  • the electrode and the first through hole are arranged on the same side wall, and there is no need to reserve space for the pressure relief mechanism to achieve pressure relief, which can save space in the electrical equipment and make the structure of the electrical equipment more compact.
  • the electrochemical device further includes a pole, and the pole and the first through hole are disposed on different side walls.
  • the pole can be used to connect with the circuit board, by arranging the pole and the first through hole on different side walls, it is possible to make it difficult for the electrolyte inside the electrochemical device to pass through the first pressure relief channel after the pressure relief mechanism forms the first pressure relief channel.
  • the electrolyte can be sprayed onto the circuit board to reduce the possibility of short circuiting components on the circuit board.
  • the score groove is arranged near a corner of the housing.
  • the electrochemical device further comprises a pole, wherein the pole is disposed on the housing, and the notched groove is located near an end of the housing where the pole is disposed.
  • a spacing space is formed between the electrode assembly and the outer shell on the side where the pole is arranged in the electrochemical device.
  • the notch groove is arranged in an arc shape and is bent toward the center of the shell cover or the bottom wall where the notch groove is located.
  • the processing and forming of the notch groove can be facilitated, and when the pressure inside the shell is high, the middle part of the shell cover or the bottom wall is subjected to greater force, so the notch groove is more likely to rupture and form a larger pressure relief port, which is convenient for the rapid discharge of the gas inside the shell and has higher pressure relief reliability.
  • the width of the scoring groove gradually decreases toward the interior of the shell.
  • the processing cost of the notch groove can be reduced, and the possibility of thermal deformation of the shell cover or bottom wall where the notch groove is located can be reduced.
  • the maximum width of the score groove is W, satisfying 0.02 mm ⁇ W ⁇ 0.5 mm.
  • the notch groove can be easily broken when the pressure inside the shell is high, the pressure relief reliability is high, and the cost of the notch groove is low.
  • the notch groove is not easy to break when the electrochemical device falls or is subjected to external force.
  • the notch groove can be further made to rupture easily when the pressure inside the shell is high, and the pressure relief reliability is high.
  • the cost of the notch groove is low, and the notch groove is not easy to rupture when the electrochemical device falls or is subjected to external force.
  • the maximum width W of the notch groove by setting the maximum width W of the notch groove at 0.06mm to 0.18mm, it can be further made that when the pressure inside the shell is large, the notch groove is easy to rupture, the pressure relief reliability is high, and the cost of the notch groove is low.
  • the notch groove is not easy to rupture when the electrochemical device falls or is subjected to external force.
  • the thickness S2 of the second wall satisfies 0.03 mm ⁇ S2 ⁇ 0.3 mm.
  • the second wall S2 by setting the second wall S2 to 0.03 mm to 0.3 mm, the second wall is not easily deformed by force or heat, and the second wall occupies a smaller space, which is beneficial to improving the energy density of the electrochemical device.
  • the present application provides an electrical equipment, comprising the electrochemical device as described above, wherein the electrochemical device is used to provide electrical energy.
  • FIG1 is a schematic diagram of a three-dimensional structure of an electrochemical device provided in some embodiments of the present application.
  • FIG2 is a schematic diagram of an exploded structure of an electrochemical device provided in some embodiments of the present application.
  • FIG3 is a schematic cross-sectional view of an electrochemical device provided in some embodiments of the present application.
  • FIG4 is a schematic diagram of a partial enlarged structure of the electrochemical device at A shown in FIG3 ;
  • FIG5 is a schematic structural diagram of a partial structure of an electrochemical device provided in some embodiments of the present application from one perspective;
  • FIG6 is a schematic diagram of a three-dimensional structure of an electrochemical device provided in some other embodiments of the present application.
  • FIG7 is a cross-sectional schematic diagram of a partial structure of the electrochemical device provided in the embodiment of FIG6 ;
  • FIG8 is a schematic diagram of a three-dimensional structure of an electrochemical device provided in some other embodiments of the present application.
  • FIG9 is a schematic cross-sectional view of a partial structure of the electrochemical device provided in the embodiment of FIG8 ;
  • FIG10 is a schematic structural diagram of an adhesive film of an electrochemical device provided by some embodiments of the present application from one perspective;
  • FIG11 is a schematic cross-sectional structure diagram of an adhesive film of an electrochemical device provided by some embodiments of the present application from another perspective;
  • FIG12 is a schematic structural diagram of an electrochemical device provided in some embodiments of the present application from one perspective;
  • FIG13 is a schematic cross-sectional view of an electrochemical device provided in some embodiments of the present application from another perspective;
  • FIG. 14 is a schematic diagram of a partial enlarged structure of a portion B of the electrochemical device shown in FIG. 13 .
  • Icons 10-electrochemical device; 100-housing; 101-first through hole; 102-notched groove; 110-shell; 111-bottom wall; 112-first side wall; 113-second side wall; 114-third side wall; 115-fourth side wall; 120-shell cover; 200-pressure relief mechanism; 210-adhesive film; 211-first adhesive layer; 212-second adhesive layer; 213-third adhesive layer; 220-first metal sheet; 230-second metal sheet; 231-second through hole; 300-electrode column; 400-electrode assembly.
  • the electrochemical device may be a secondary battery or a primary battery; for example, the electrochemical device may be a lithium-ion battery, a sodium-ion battery, or a magnesium-ion battery, etc., which is not limited in the embodiments of the present application.
  • the electrochemical device may be cylindrical, flat, rectangular, or in other shapes, etc., which is not limited in the embodiments of the present application.
  • the electrode assembly may be a wound structure or a laminated structure, which is not limited in the embodiments of the present application.
  • Electrochemical devices have outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide range of applications, and low self-discharge coefficient. They are an important part of the development of new energy today.
  • electrochemical devices mainly form notched grooves by laser notching on the shell cover, so that when the internal gas pressure of the electrochemical device is too high, the notched grooves can rupture to form a pressure relief channel to discharge the gas inside the battery cell and play an explosion-proof role.
  • the notched grooves mainly rely on the gas pressure inside the electrochemical device to rupture, and have poor thermal sensitivity. The pass rate of the hot box test is low. When the temperature of the electrochemical device is high and the gas pressure does not reach the preset value, the probability of the notched grooves rupturing is low, and there is still a risk of thermal runaway of the electrochemical device.
  • the present application provides an electrochemical device, the electrochemical device includes a shell and a pressure relief mechanism, the shell includes a first wall and a second wall, the first wall is provided with a first through hole, the pressure relief mechanism covers the first through hole, the pressure relief mechanism includes a film, the film can be melted or debonded by heat to form a first pressure relief channel connecting the inside and outside of the shell, the second wall is provided with a notch groove, the notch groove can be broken when the internal pressure of the shell reaches a threshold value to form a second pressure relief channel connecting the inside and outside of the shell; the depth of the notch groove is S1, the thickness of the second wall is S2, and 0.1*S2 ⁇ S1 ⁇ 0.95*S2 is satisfied.
  • the first pressure relief channel When the temperature of the electrochemical device is high, the first pressure relief channel can be formed, and when the internal pressure of the electrochemical device is high, the second pressure relief channel can be formed, so that the electrochemical device can form two pressure relief channels to adapt to different situations, which can improve the pressure relief sensitivity and pressure relief reliability of the electrochemical device and reduce the probability of thermal runaway of the electrochemical device. And by making 0.1*S2 ⁇ S1 ⁇ 0.95*S2, when the pressure inside the shell is large, the notched groove is easy to rupture, the pressure relief reliability is high, and the cost of the notched groove is low.
  • the notched groove is not easy to rupture when the electrochemical device falls or is subjected to external force; when the notched groove is deep, the pressure relief response is fast, but too deep is easy to cause rupture, and when the notched groove is shallow, it is not easy to rupture, but the pressure relief response is slow; by In the above technical solution, limiting the depth of the notched groove can balance the relationship between the two, and because the present solution is a joint action of the pressure relief mechanism and the notched groove, the depth of the notched groove can be made smaller without causing the problem of slow pressure relief response.
  • the embodiment of the present application provides an electric device using an electrochemical device as a power source
  • the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc.
  • the electric toy may include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, an electric airplane toy, etc.
  • the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, etc.
  • the electrochemical device described in the embodiments of the present application is not limited to the electrical equipment described above, but can also be applied to all electrical equipment using the electrochemical device.
  • FIG. 1 is a schematic diagram of the three-dimensional structure of an electrochemical device provided in some embodiments of the present application
  • FIG. 2 is a schematic diagram of the exploded structure of an electrochemical device provided in some embodiments of the present application.
  • the electrochemical device 10 includes a housing 100, a pole 300, and an electrode assembly 400.
  • the housing 100 is formed with a receiving space, and the receiving space is used to accommodate the electrode assembly 400 and the electrolyte.
  • the pole 300 is arranged through the housing 100 and is electrically connected to the electrode assembly 400.
  • the electrode assembly 400 is composed of a positive electrode plate, a negative electrode plate, and a separator.
  • the positive electrode plate includes a positive electrode current collector and a positive electrode active material layer, and the positive electrode active material layer is coated on the surface of the positive electrode current collector.
  • the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganate, etc.
  • the negative electrode plate includes a negative electrode current collector and a negative electrode active material layer, and the negative electrode active material layer is coated on the surface of the negative electrode current collector.
  • the material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon, etc.
  • the electrochemical device 10 mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work.
  • the temperature of the electrochemical device 10 will increase, and the electrode assembly 400 may generate gas, causing the pressure inside the housing 100 to increase.
  • the pressure inside the housing 100 continues to accumulate and increase, which may cause an explosion, and the excessive temperature of the electrochemical device 10 may cause thermal runaway, which may cause damage to the electrochemical device 10.
  • the electrochemical device 10 includes a housing 100 and a pressure relief mechanism 200
  • the housing 100 includes a first wall and a second wall
  • the first wall is provided with a first through hole 101.
  • the pressure relief mechanism 200 covers the first through hole 101
  • the pressure relief mechanism 200 includes a film 210, which can be melted or debonded by heat to form a first pressure relief channel connecting the inside and outside of the housing 100.
  • the second wall is provided with a notched groove 102, which can be broken when the internal pressure of the housing 100 reaches a threshold value to form a second pressure relief channel connecting the inside and outside of the housing 100.
  • the depth of the notched groove 102 is S1, and the thickness of the second wall is S2, satisfying 0.1*S2 ⁇ S1 ⁇ 0.95*S2.
  • S1 can be 0.1*S2, 0.5*S2 or 0.95*S2, etc.
  • the notch groove 102 may be formed by laser etching.
  • the pressure relief mechanism 200 covers the first through hole 101 of the first wall, and the pressure relief mechanism 200 includes a film 210, which can melt or lose adhesion when heated to form a first pressure relief channel connecting the inside and outside of the shell 100.
  • the second wall is also provided with a notch groove 102, which can rupture when the internal pressure of the shell 100 reaches a threshold value to form a second pressure relief channel connecting the inside and outside of the shell 100, that is, when the temperature of the electrochemical device 10 is high, the first pressure relief channel can be formed, and when the internal pressure of the electrochemical device 10 is high, the second pressure relief channel can be formed, so that the electrochemical device 10 can form two pressure relief channels.
  • the pressure relief mechanism 200 can effectively sense the heat generation of the electrochemical device 10 and generate pressure relief when the melting point is reached.
  • the electrochemical device 10 encounters some working conditions with less heat generation and more gas generation, such as over-discharge, the electrochemical device 10 generates less heat and produces more gas, so pressure relief is required.
  • the pressure relief mechanism 200 is sensitive to temperature and may fail to relieve pressure in time.
  • the notched groove 102 can effectively sense the gas production of the electrochemical device 10. When the gas production reaches a certain level, the outer shell expands and deforms, and the notched groove 102 opens.
  • the above scheme can adapt to different situations, improve the pressure relief sensitivity and reliability of the electrochemical device 10, and reduce the probability of thermal runaway of the electrochemical device 10.
  • the depth S1 of the notched groove 102 and the thickness S2 of the second wall satisfy 0.1*S2 ⁇ S1 ⁇ 0.95*S2, when the pressure inside the housing 100 is high, the notched groove 102 can be easily broken, the pressure relief reliability is high, and the cost of the notched groove 102 is low.
  • the notched groove 102 is not easy to break when the electrochemical device 10 falls or is acted upon by external force. When the notched groove 102 is deeper, the pressure relief response is fast, but it is easy to cause rupture if it is too deep.
  • the depth of the notched groove 102 can be made smaller without causing the problem of slow pressure relief response; if only a single notched groove 102 pressure relief function is provided in the electrochemical device 10, because the pressure relief sensitivity of the notched groove 102 is low, the notched groove 102 needs to be deepened, but when the notched groove 102 is deeper, there are problems of rolling, falling and leakage, and the cost of the notched groove 102 is high.
  • the present solution uses a multi-channel pressure relief structure, so the depth of the notched groove 102 can be limited to the above range.
  • the pressure relief mechanism 200 may also form a first pressure relief channel under the action of pressure, thereby accelerating the discharge of gas.
  • the first through hole 101 may be a liquid injection hole, through which liquid is injected into the electrochemical device 10. Inject electrolyte.
  • the preparation process of the electrochemical device 10 can be further simplified, the number of drilling steps can be reduced, and the preparation cost of the electrochemical device 10 can be reduced.
  • the first through hole 101 may also be other through holes formed in the housing 100 .
  • S1 may be 0.4*S2, 0.6*S2, or 0.8*S2.
  • the depth S1 of the notched groove 102 and the thickness S2 of the second wall satisfy 0.4*S2 ⁇ S1 ⁇ 0.8*S2, it is possible to further ensure that when the pressure inside the housing 100 is high, the notched groove 102 is easy to rupture, the pressure relief reliability is high, and the cost of the notched groove 102 is low.
  • the notched groove 102 is not likely to rupture when the electrochemical device 10 falls or is subjected to external force.
  • S1 may be 0.55*S2, 0.65*S2, or 0.8*S2.
  • the depth S1 of the notched groove 102 and the thickness S2 of the second wall satisfy 0.55*S2 ⁇ S1 ⁇ 0.8*S2, it is possible to further make the notched groove 102 easy to rupture when the pressure inside the shell 100 is high, and the pressure relief reliability is high. In addition, the cost of the notched groove 102 is low, and the notched groove 102 is not likely to rupture when the electrochemical device 10 falls or is acted upon by external force.
  • the hot melt pressure relief (pressure relief mechanism 200) of the present scheme with the notched groove 102 in the shell of the same electrochemical device 10, it is possible to make the depth S1 of the notched groove 102 and the thickness S2 of the second wall satisfy 0.55*S2 ⁇ S1 ⁇ 0.8*S2.
  • the pressure relief mechanism 200 may further include a first metal sheet 220 , and the first metal sheet 220 is disposed on a side of the adhesive film 210 facing away from the housing 100 .
  • the first metal sheet 220 is stacked with the adhesive film 210 along the thickness direction of the adhesive film 210. Since the adhesive film 210 is a high molecular polymer and is water permeable, after water enters the interior of the housing 100 through the adhesive film 210, it will have an adverse effect on the electrode assembly 400 and the electrolyte. By arranging the first metal sheet 220 on the side of the adhesive film 210 facing away from the housing 100, the first metal sheet 220 can cover at least part of the adhesive film 210, which can reduce the water seepage area of the adhesive film 210, so that the sealing effect is better, and the service life of the electrochemical device 10 is extended.
  • the adhesive film 210 may be made of a high molecular polymer, such as polypropylene (PP), which has good toughness and good chemical resistance.
  • PP polypropylene
  • the first metal sheet 220 can be made of aluminum, nickel, stainless steel or other materials, which is not easy to rust and has a long service life.
  • Figure 3 is a schematic diagram of the cross-sectional structure of the electrochemical device provided in some embodiments of the present application
  • Figure 4 is a schematic diagram of the local enlarged structure of point A of the electrochemical device shown in Figure 3
  • Figure 5 is a schematic diagram of the structure of a partial structure of the electrochemical device provided in some embodiments of the present application from one perspective.
  • the first metal sheet 220 is arranged in a circular shape
  • the adhesive film 210 is arranged in a circular shape
  • the first through hole 101 is arranged in a circular shape
  • the diameter D4 of the first metal sheet 220 is less than or equal to the outer diameter D2 of the adhesive film 210
  • the diameter D4 of the first metal sheet 220 is greater than or equal to the diameter D1 of the first through hole 101.
  • the first metal sheet 220 By setting the first metal sheet 220 in a circular shape, there is no need to adjust the assembly direction of the first metal sheet 220, which can facilitate the transfer of the first metal sheet 220 and the adhesive film 210.
  • the adhesive film 210 By setting the adhesive film 210 in a circular shape and the first through hole 101 in a circular shape, there is no need to adjust the assembly direction of the adhesive film 210, which can facilitate the assembly of the adhesive film 210 and the housing 100.
  • the axis of the adhesive film 210 is collinear with the axis of the first through hole 101, the contact surface of the adhesive film 210 and the housing 100 is evenly distributed, and the sealing effect is better.
  • the diameter D4 of the first metal sheet 220 smaller than or equal to the outer diameter D2 of the adhesive film 210, the possibility of the first metal sheet 220 shielding the adhesive film 210 can be reduced when the first metal sheet 220, the adhesive film 210 and the housing 100 are assembled, which facilitates the positioning of the adhesive film 210 on the housing 100, so that the adhesive film 210 covers the first through hole 101, thereby facilitating the assembly of the adhesive film 210, the first metal sheet 220 and the housing 100, and the pressure relief mechanism 200 and the housing 100 are better sealed.
  • the first metal sheet 220 can cover the first through hole 101, reducing the possibility of water vapor penetrating into the interior of the housing 100 through the adhesive film 210 and the first through hole 101, so that the sealing effect of the pressure relief mechanism 200 is better.
  • the first through hole 101 may be arranged in a racetrack shape, a rectangle, or an ellipse shape.
  • the first through hole 101 in a racetrack shape, a rectangle or an ellipse, when the thickness of the electrochemical device 10 is small, the area of the first through hole 101 is large, and the pressure relief reliability is high.
  • the first metal sheet 220 may also be provided in an oval, square, etc.
  • the adhesive film 210 may also be provided in an oval, square, etc. shape.
  • the adhesive film 210 can also be arranged in a circular ring shape, and there is no need to adjust the assembly direction of the adhesive film 210, which can facilitate the assembly of the adhesive film 210 and the housing 100.
  • the axis of the adhesive film 210 is in line with the axis of the first through hole 101, the contact surface of the adhesive film 210 and the housing 100 is evenly distributed, and the sealing effect is better.
  • a first pressure relief channel can be formed between the adhesive film 210 and the housing 100, and between the adhesive film 210 and the first metal sheet 220, which can increase the number of first pressure relief channels, so that The pressure relief sensitivity is higher and the pressure relief effect is better.
  • the adhesive film 210 may also be provided in an elliptical ring shape, a square ring shape, or the like.
  • the pressure relief mechanism 200 may further include a second metal sheet 230 , which is disposed between the adhesive film 210 and the housing 100 , is welded to the housing 100 , and is provided with a second through hole 231 .
  • the second metal sheet 230 can be made of aluminum, nickel, stainless steel or other materials, which is not easy to rust and has a long service life.
  • the second metal sheet 230 and the housing 100 may be welded by laser welding.
  • the adhesive film 210 can be activated by high temperature to melt and adhere to the second metal sheet 230. After the adhesive film 210 is cooled, it is fixed on the second metal sheet 230, and can seal the first through hole 101 and the second through hole 231. When the adhesive film 210 is heated and melted or loses its adhesion again, it at least partially separates from the second metal sheet 230 to form a first pressure relief channel.
  • the connection between the pressure relief mechanism 200 and the housing 100 can be made more stable and the sealing effect can be better.
  • the first through hole 101 is reused as the injection hole, electrolyte residue may exist at the injection hole of the electrochemical device 10 after the injection is completed.
  • the electrolyte may affect the viscosity of the adhesive film 210, making the adhesive film 210 and the housing 100 not firmly attached. Therefore, by providing a second metal sheet 230 for welding with the housing 100, the connection between the pressure relief mechanism 200 and the housing 100 can be further stabilized and the sealing effect can be better.
  • the adhesive film 210 can be firstly bonded to the first metal sheet 220 and the second metal sheet 230 respectively to form a pressure relief mechanism 200, and then the pressure relief mechanism 200 is welded to the outer shell 100, which can make the preparation process simpler, and the pressure relief mechanism 200 can adapt to first through holes 101 of various sizes, and the pressure relief mechanism 200 has better versatility.
  • first metal sheet 220, the adhesive film 210, and the second metal sheet 230 may be stacked first, and then when the second metal sheet 230 is welded to the housing 100, the high welding temperature may melt the adhesive film 210 to simultaneously achieve the bonding of the adhesive film 210 with the first metal sheet 220 and the second metal sheet 230.
  • the second metal sheet 230 is arranged in a circular ring shape, the outer diameter D2 of the second metal sheet 230 is greater than or equal to the diameter D1 of the first through hole 101, the diameter D4 of the first metal sheet 220 is less than or equal to the outer diameter D2 of the second metal sheet 230, and the diameter D4 of the first metal sheet 220 is greater than or equal to the inner diameter D3 of the second metal sheet 230.
  • the second metal sheet 230 By setting the second metal sheet 230 into a circular ring shape, the second metal sheet 230 can form a first pressure relief channel, so that the pressure relief effect of the pressure relief mechanism 200 is better.
  • the outer diameter D2 of the second metal sheet 230 By making the outer diameter D2 of the second metal sheet 230 greater than or equal to the diameter D1 of the first through hole 101, it is convenient to weld the second metal sheet 230 with the housing 100.
  • the diameter D4 of the first metal sheet 220 less than or equal to the outer diameter D2 of the second metal sheet 230, when the first metal sheet 220, the adhesive film 210, the second metal sheet 230 and the housing 100 are assembled, the possibility of the first metal sheet 220 blocking the second metal sheet 230 can be reduced, and the positioning of the second metal sheet 230 on the housing 100 is facilitated, so that the second metal sheet 230 covers the first through hole 101, thereby facilitating the assembly of the adhesive film 210, the first metal sheet 220, the second metal sheet 230 and the housing 100, and the pressure relief mechanism 200 and the housing 100 are better sealed.
  • the first metal sheet 220 can cover the second through hole 231, reducing the possibility of water vapor penetrating into the interior of the housing 100 through the adhesive film 210 and the second through hole 231, so that the sealing effect of the pressure relief mechanism 200 is better.
  • the second metal sheet 230 may also be provided in the shape of an elliptical ring, a square ring, or the like.
  • the diameter of the first through hole 101 is D1
  • the outer diameter of the second metal sheet 230 is D2
  • the inner diameter of the second metal sheet 230 is D3, which satisfies 0.2 mm ⁇ D1 ⁇ 5 mm, 1 mm ⁇ D2 ⁇ 6 mm, and 0.1 mm ⁇ D3 ⁇ 3 mm.
  • D1 may be 0.2 mm, 3 mm, or 5 mm
  • D2 may be 1 mm, 4 mm, or 6 mm
  • D3 may be 0.1 mm, 1.2 mm, or 3 mm.
  • the inner diameter D3 of the second metal sheet 230 is the diameter of the second through hole 231 .
  • the first through hole 101 can provide a first pressure relief channel with a larger cross-sectional area when the electrochemical device 10 is in thermal runaway, and there is no need for a large-sized pressure relief mechanism 200 to cover the first through hole 101, which facilitates the installation of the pressure relief mechanism 200 and saves the cost of the pressure relief mechanism 200.
  • the outer diameter D2 of the second metal sheet 230 to 1 mm to 6 mm, the second metal sheet 230 has enough area to fit with the housing 100, which can facilitate the welding of the second metal sheet 230 and the housing 100, and the second metal sheet 230 will not exceed the housing 100, which is low in cost.
  • the second through hole 231 can provide a first pressure relief channel with a larger cross-sectional area, and there is no need for a larger-sized adhesive film 210 and a first metal sheet 220 to cover the second through hole, which facilitates the installation of the adhesive film 210 and the first metal sheet 220 and saves the cost of the adhesive film 210 and the first metal sheet 220.
  • the cross-sectional area of the first through hole 101 is the cross-sectional area of the first through hole 101 on a plane parallel to its radial direction.
  • the second metal sheet 230 does not extend beyond the housing 100, which means that the second metal sheet 230 does not extend beyond the edge of the housing 100 in its radial direction.
  • the outer diameter D2 of the second metal sheet 230 satisfies 2mm ⁇ D2 ⁇ 5mm.
  • D2 may be 2mm, 3mm, or 5mm.
  • the second metal sheet 230 can further have enough area to fit with the housing 100, which can facilitate welding of the second metal sheet 230 and the housing 100, and the second metal sheet 230 will not exceed the housing 100, which is low in cost.
  • the inner diameter D3 of the second metal sheet 230 satisfies 0.3mm ⁇ D3 ⁇ 1.5mm.
  • D3 may be 0.3mm, 1mm, or 1.5mm.
  • the inner diameter D3 of the second metal sheet 230 it is possible to further enable the second through hole 231 to provide a first pressure relief channel with a larger cross-sectional area when the first pressure relief channel is formed through the second through hole 231, and it is not necessary to cover the second through hole with a larger size of the adhesive film 210 and the first metal sheet 220, which facilitates the installation of the adhesive film 210 and the first metal sheet 220 and saves the cost of the adhesive film 210 and the first metal sheet 220.
  • the thickness of the first metal sheet 220 is H1
  • the thickness of the second metal sheet 230 is H2, satisfying 0.03 mm ⁇ H1 ⁇ 1 mm, 0.03 mm ⁇ H2 ⁇ 1 mm.
  • H1 can be 0.03 mm, 0.5 mm, or 1 mm
  • H2 can be 0.03 mm, 0.4 mm, or 1 mm, etc.
  • the sealing effect of the first metal sheet 220 and the second metal sheet 230 is improved, the possibility of water vapor penetrating into the interior of the housing 100 is reduced, and the thickness of the pressure relief mechanism 200 can be reduced, so that the pressure relief mechanism 200 occupies less space in the length direction of the electrochemical device 10, and more space of the electrochemical device 10 can be used to set the electrode assembly 400, which is beneficial to improve the energy density of the electrochemical device 10.
  • the thickness H1 of the first metal sheet 220 satisfies 0.05 mm ⁇ H1 ⁇ 0.15 mm
  • the thickness H2 of the second metal sheet 230 satisfies 0.05 mm ⁇ H2 ⁇ 0.15 mm.
  • H1 may be 0.05 mm, 0.1 mm, or 0.15 mm
  • H2 may be 0.05 mm, 0.11 mm, or 0.15 mm, etc.
  • the sealing effect of the first metal sheet 220 and the second metal sheet 230 can be further improved, the possibility of water vapor penetrating into the interior of the housing 100 can be reduced, and the thickness of the pressure relief mechanism 200 can be reduced, so that the pressure relief mechanism 200 occupies less space in the length direction of the electrochemical device 10, and more space of the electrochemical device 10 can be used to set the electrode assembly 400, which is conducive to improving the energy density of the electrochemical device 10.
  • the thickness of the adhesive film 210 is H3, which satisfies 0.05 mm ⁇ H3 ⁇ 1 mm.
  • H3 may be 0.05 mm, 0.4 mm, or 1 mm.
  • the adhesive film 210 can be made not easily damaged, has low water permeability, and is easily melted or debonded at high temperature to form a first pressure relief channel, so that the pressure relief sensitivity of the pressure relief mechanism 200 is higher and the pressure relief effect is better.
  • the adhesive force with the first metal sheet 220 and the second metal sheet 230 is stronger, and the sealing effect on the first through hole 101 is better.
  • the thickness H3 of the adhesive film 210 satisfies 0.1mm ⁇ H3 ⁇ 0.3mm.
  • H3 may be 0.1mm, 0.2mm, or 0.3mm, etc.
  • the adhesive film 210 can be further made less prone to damage, less permeable, and easily melted or debonded at high temperatures to form a first pressure relief channel, so that the pressure relief mechanism 200 has a higher pressure relief sensitivity and a better pressure relief effect, and has a stronger adhesion to the first metal sheet 220 and the second metal sheet 230 at room temperature, and has a better sealing effect on the first through hole 101.
  • FIG. 6 is a schematic diagram of a three-dimensional structure of an electrochemical device provided in some other embodiments of the present application
  • FIG. 7 is a schematic diagram of a cross-sectional view of a partial structure of the electrochemical device provided in the embodiment of FIG. 6 .
  • the pressure relief mechanism 200 may only include the adhesive film 210, which can melt or lose adhesion due to heat to form a first pressure relief channel connecting the inside and outside of the housing 100, so that the electrochemical device 10 can be pressure-relieved through the pressure relief mechanism 200 when the temperature is high.
  • the pressure relief sensitivity and reliability of the electrochemical device 10 are high, which can reduce the probability of thermal runaway of the electrochemical device 10.
  • FIG. 8 is a schematic diagram of the three-dimensional structure of electrochemical devices provided in other embodiments of the present application
  • FIG. 9 is a schematic diagram of the cross-sectional structure of a portion of the electrochemical device provided in the embodiment of FIG. 8 .
  • the pressure relief mechanism 200 may only include the adhesive film 210 and the first metal sheet 220.
  • the adhesive film 210 can be melted or debonded by heat to form a first pressure relief channel connecting the inside and outside of the housing 100, so that the electrochemical device 10 can be opened at a high temperature.
  • the pressure can be released through the pressure release mechanism 200.
  • the pressure release sensitivity and reliability of the electrochemical device 10 are high, which can reduce the probability of thermal runaway of the electrochemical device 10.
  • the first metal sheet 220 can reduce the water seepage area of the adhesive film 210, so that the sealing effect is better, thereby extending the service life of the electrochemical device 10.
  • FIG. 10 is a schematic structural diagram of an adhesive film of an electrochemical device provided in some embodiments of the present application from one perspective
  • FIG. 11 is a schematic cross-sectional structural diagram of an adhesive film of an electrochemical device provided in some embodiments of the present application from another perspective.
  • the adhesive film 210 includes a first adhesive layer 211, a second adhesive layer 212 and a third adhesive layer 213.
  • the second adhesive layer 212, the first adhesive layer 211 and the third adhesive layer 213 are stacked in sequence.
  • the second adhesive layer 212 is located on the side of the first adhesive layer 211 facing away from the outer shell 100.
  • the melting point of the first adhesive layer 211 is lower than the melting point of the second adhesive layer 212.
  • the third adhesive layer 213 is located between the second adhesive layer 212 and the first metal sheet 220. The melting point of the third adhesive layer 213 is lower than the melting point of the second adhesive layer 212.
  • the second adhesive layer 212, the first adhesive layer 211, and the third adhesive layer 213 are stacked along the thickness direction of the adhesive film 210.
  • the melting point of the first adhesive layer 211 lower than the melting point of the second adhesive layer 212, and the melting point of the third adhesive layer 213 lower than the melting point of the second adhesive layer 212, when the adhesive film 210 is activated by high temperature, the first adhesive layer 211 can melt to fit with the housing 100, and the third adhesive layer 213 can melt to fit with the first metal sheet 220, while the second adhesive layer 212 will not melt, so that the adhesive film 210 can be prevented from being over-melted and affecting the installation of the adhesive film 210, and the amount of adhesive overflow can be reduced.
  • two first pressure relief channels can be formed between the first adhesive layer 211 and the housing 100, and between the third adhesive layer 213 and the first metal sheet 220, respectively.
  • the pressure relief reliability of the pressure relief mechanism 200 in this embodiment is higher, and the probability that the first pressure relief channel cannot be formed can be reduced.
  • the pressure relief speed of the pressure relief mechanism 200 can be increased. Therefore, the three-layer structure of the adhesive film 210 can improve the pressure relief sensitivity and reliability of the electrochemical device 10, and reduce the probability of thermal runaway of the electrochemical device 10.
  • the melting point of the first adhesive layer 211 is T1
  • the melting point of the second adhesive layer 212 is T2
  • the melting point of the third adhesive layer 213 is T3, satisfying 95°C ⁇ T1 ⁇ 135°C, 140°C ⁇ T2 ⁇ 190°C, and 95°C ⁇ T3 ⁇ 135°C.
  • T1 may be 95°C, 100°C, or 135°C, etc.
  • T2 may be 95°C, 105°C, or 135°C, etc.
  • T3 may be 95°C, 110°C, or 135°C, etc.
  • the sealing reliability of the adhesive film 210 to the first through hole 101 can be higher, and the first adhesive layer 211 can melt before the second adhesive layer 212, so that it is convenient to install it on the housing 100 when the adhesive film 210 is activated at high temperature, and the third adhesive layer 213 can melt before the second adhesive layer 212, so that it is convenient to install it on the first metal sheet 220 when the adhesive film 210 is activated at high temperature.
  • the first adhesive layer 211 can melt or lose adhesion before the second adhesive layer 212 to form a first pressure relief channel
  • the third adhesive layer 213 can melt or lose adhesion before the second adhesive layer 212 to form a first pressure relief channel, so that the pressure relief sensitivity of the electrochemical device 10 is higher and the amount of adhesive overflow of the adhesive film 210 can be reduced.
  • the adhesive film 210 may be a single-layer structure, and the melting point of the adhesive film 210 is T, satisfying 95° C. ⁇ T ⁇ 135° C.
  • T may be 95° C., 120° C., or 135° C.
  • the sealing reliability of the adhesive film 210 to the first through hole 101 can be higher, and when the electrochemical device 10 is in thermal runaway, the adhesive film 210 can melt or lose adhesion to form a first pressure relief channel, so that the pressure relief sensitivity of the electrochemical device 10 is higher.
  • the adhesive film 210 can be a double-layer structure, including a first adhesive layer 211 and a second adhesive layer 212, the first adhesive layer 211 and the second adhesive layer 212 are stacked, the second adhesive layer 212 is located on the side of the first adhesive layer 211 facing away from the shell 100, and the melting point of the first adhesive layer 211 is less than the melting point of the second adhesive layer 212.
  • the adhesive film 210 By setting the adhesive film 210 to a double-layer structure, and the adhesive film 210 includes a first adhesive layer 211 and a second adhesive layer 212, and making the melting point of the first adhesive layer 211 lower than the melting point of the second adhesive layer 212, when the adhesive film 210 is activated by high temperature, the first adhesive layer 211 can melt to fit with the housing 100, and the second adhesive layer 212 will not melt, which can prevent the adhesive film 210 from over-melting and affecting the installation of the adhesive film 210, and can also reduce the amount of adhesive overflow of the adhesive film 210.
  • the melting point of the first adhesive layer 211 is T1
  • the melting point of the second adhesive layer 212 is T2, satisfying 95° C. ⁇ T1 ⁇ 135° C., 140° C. ⁇ T2 ⁇ 190° C.
  • T1 may be 95° C., 100° C., or 135° C.
  • T2 may be 95° C., 105° C., or 135° C., etc.
  • the housing 100 may be provided with a groove (not shown in the figure), the first through hole 101 passes through the groove, and the pressure relief mechanism 200 is accommodated in the groove.
  • the pressure relief mechanism 200 is accommodated in the groove, so that the thickness of the portion of the pressure relief mechanism 200 that extends beyond the outer surface of the shell is smaller, thereby reducing the possibility of the pressure relief mechanism 200 interfering with other components and being damaged or detaching from the shell 100.
  • the pressure relief mechanism 200 does not extend beyond the outer surface of the housing, which can further reduce the pressure relief mechanism 200 and its The possibility of interference with other components and damage or separation from the housing 100 is avoided.
  • Figure 12 is a schematic structural diagram of an electrochemical device provided in some embodiments of the present application from one perspective
  • Figure 13 is a schematic cross-sectional structural diagram of an electrochemical device provided in some embodiments of the present application from another perspective.
  • the housing 100 includes a shell 110 and a shell cover 120
  • the shell 110 includes a bottom wall 111 and multiple side walls surrounding the bottom wall 111, the bottom wall 111 and the multiple side walls together form a accommodating space with an opening, the shell cover 120 closes the opening, the side wall is the first wall body, and the bottom wall 111 or the shell cover 120 is the second wall body.
  • the shell cover 120 is configured in a plate shape, and the shell cover 120 closes an opening formed by the housing 110 .
  • the shell cover 120 may also be a hollow structure with one end open, and the open side of the shell cover 120 covers the open side of the housing 110 to form an accommodation space.
  • the notched groove 102 may be disposed on the wall of the shell cover 120 opposite to the bottom wall 111 .
  • the shell 110 and the shell cover 120 can be made of aluminum, nickel, stainless steel or other materials, so that the outer shell 100 has a higher force-bearing performance, is not easy to rust, and has a longer service life.
  • the shell 110 , the shell cover 120 and the second metal sheet 230 may be made of the same metal material to facilitate welding of the shell 110 and the shell cover 120 , and to facilitate welding of the shell 110 and the second metal sheet 230 .
  • the housing 110 and the housing cover 120 may be fixedly connected by laser welding.
  • the possibility of the first pressure relief channel being blocked can be reduced, and the pressure relief reliability of the pressure relief mechanism 200 is high.
  • the notched groove 102 on the bottom wall 111 of the housing 110 or the housing cover 120, a second pressure relief channel with a larger size can be formed, which facilitates the rapid discharge of gas inside the housing 100, and the pressure relief reliability is high.
  • a plurality of first through holes 101 may be provided on the side wall of the housing 110, and the plurality of first through holes 101 are arranged at intervals.
  • a film 210 may be disposed on each first through hole 101, and the film 210 covers the first through hole 101.
  • the melting points of the plurality of films 210 may be different, so as to automatically adjust the pressure relief speed when the temperature of the electrochemical device 10 is high. For example, when the temperature of the electrochemical device 10 reaches the melting point temperature of the film 210 with the lowest melting point, the film 210 melts or loses adhesion and forms a first pressure relief channel, and the pressure relief speed is slow.
  • the other films 210 melt or lose adhesion in turn and form the first pressure relief channel, and the pressure relief speed is accelerated, that is, the higher the temperature of the electrochemical device 10, the faster the pressure relief speed of the electrochemical device 10, which can further reduce the possibility of thermal runaway of the electrochemical device 10.
  • a plurality of notched grooves 102 may be provided on the bottom wall 111 and/or the shell cover 120, and the plurality of notched grooves 102 are arranged at intervals.
  • two notched grooves 102 are provided on the shell cover 120, and the two notched grooves 102 are respectively provided at two top corners of the shell cover 120 close to the pole 300, and are symmetrically provided, so that when the gas inside the shell 100 is discharged through the pressure relief port formed by the rupture of the two notched grooves 102, the shell cover 120 is subjected to force more evenly and is not easy to produce large deformation to squeeze other devices.
  • the bottom wall 111 and the shell cover 120 may be the two surfaces with the largest area on the outer surface of the electrochemical device 10.
  • the bottom wall 111 and the shell cover 120 are easily deformed. Therefore, the notched groove 102 is arranged on the bottom wall 111 or the shell cover 120, and the notched groove 102 is more likely to rupture when the internal pressure of the electrochemical device 10 is relatively high.
  • the first pressure relief channel is formed by the pressure relief mechanism 200
  • the second pressure relief channel is formed by the notched groove 102, which can reduce the gas flowing out through the second pressure relief channel, so that the bottom wall 111 or the shell cover 120 where the notched groove 102 is located is subjected to less pressure, and is not prone to large deformation, thereby reducing the risk of squeezing other devices.
  • the plurality of side walls may include a first side wall 112, a second side wall 113, a third side wall 114, and a fourth side wall 115, the first side wall 112 is disposed opposite to the third side wall 114, the second side wall 113 is disposed opposite to the fourth side wall 115, the first side wall 112 is respectively connected to the second side wall 113 and the fourth side wall 115, and the third side wall 114 is respectively connected to the second side wall 113 and the fourth side wall 115.
  • the electrochemical device 10 further includes a pole 300, and the pole 300 and the first through hole 101 are disposed on the same side wall (e.g., the first side wall 112).
  • the pole 300 and the first through hole 101 may also be disposed on different side walls.
  • the pole 300 is disposed on the first side wall 112
  • the first through hole 101 is disposed on the second side wall 113 .
  • the pole 300 can be used to connect to a circuit board (not shown in the figure), by arranging the pole 300 and the first through hole 101 on different side walls, after the pressure relief mechanism 200 forms the first pressure relief channel, the electrolyte inside the electrochemical device 10 is not easy to splash onto the circuit board through the first pressure relief channel, thereby reducing the possibility of the electrolyte causing a short circuit in components on the circuit board.
  • the electrode column 300 and the first through hole 101 are arranged on different side walls, and the first through hole 101 is arranged close to the electrode column 300, so that the gas inside the shell 100 can pass through the interval space formed between the electrode assembly 400 and the shell 100, the pressure relief device 101 and the pressure relief device 102.
  • the first pressure relief channel formed by the structure 200 is used for discharge, and the pressure relief reliability is high.
  • the pole 300 can be fixed on the side wall of the housing 100 by riveting, welding, etc.
  • a spacing space is formed between the electrode assembly 400 and the housing 100.
  • the pole 300 can be electrically connected to other devices of the electrical device
  • the pole 300 and the first through hole 101 are arranged on the same side wall, and there is no need to reserve space for the pressure relief mechanism 200 to achieve pressure relief
  • the first side wall 112 can be the smallest in area among the multiple side walls of the housing 110, and the spacing space that needs to be reserved is also smaller, which can further save the space of the electrical device and make the structure of the electrical device more compact.
  • the score groove 102 is disposed near a corner of the housing 100 .
  • the housing 100 is in a rectangular shape, and the corners of the housing 100 are the four vertex corners of the housing 100 .
  • the bottom wall 111 or the shell cover 120 where the notched groove 102 is located is deformed, and the corners of the shell 100 are stress concentration areas of the shell 100.
  • the notched groove 102 is easily broken to form a pressure relief port, and the pressure relief reliability is higher.
  • the notched groove 102 is disposed near one end of the housing 100 where the pole 300 is disposed.
  • a spacing space is formed between the electrode assembly 400 and the shell 100.
  • the gas inside the shell 100 can be easily discharged through the spacing space and the pressure relief port formed by the rupture of the notched groove 102, which can reduce the possibility of the electrode assembly 400 blocking the pressure relief port formed by the rupture of the notched groove 102, and the pressure relief reliability is high.
  • the notched groove 102 is close to the vertex corner on the shell 100 that is closest to the pole 300, and the first through hole 101 is located on the first side wall 112 where the pole 300 is located, and close to another vertex corner of the shell 100.
  • the pressure relief mechanism 200 and the notched groove 102 are respectively located at both ends of the shell 100 in the width direction, with a certain distance, so that when the first pressure relief channel and the second pressure relief channel are both opened, the gas can be discharged from both ends of the shell 100 in the width direction respectively, and will not be concentrated at one vertex corner of the shell 100, which can reduce the possibility of deformation of the shell 100 due to local large force.
  • the notched groove 102 is arranged in an arc shape and is bent toward the center of the housing cover 120 or the bottom wall 111 where the notched groove 102 is located.
  • the notch groove 102 may be arranged in a C-shape or other arc shapes.
  • the process of etching the notched groove 102 is more continuous, which can facilitate the processing and forming of the notched groove 102. Since the middle part of the shell cover 120 or the bottom wall 111 is subjected to greater force when the internal pressure of the electrochemical device 10 is relatively high, it is more likely to deform.
  • the notched groove 102 can be closer to the center of the shell cover 120 or the bottom wall 111 where the notched groove 102 is located, and the notched groove 102 is more likely to rupture and form a larger pressure relief port, which is convenient for the rapid discharge of the gas inside the shell 100, and the pressure relief reliability is higher.
  • FIG. 14 is a schematic diagram of the local enlarged structure of the electrochemical device at B shown in FIG. 13 .
  • the width of the notch groove 102 gradually decreases toward the interior of the housing 100 .
  • gradually reducing the width of the notched groove 102 toward the interior of the shell 100 By gradually reducing the width of the notched groove 102 toward the interior of the shell 100, the processing cost of the notched groove 102 can be reduced. Since the larger the volume of the notched groove 102, the easier it is for the shell cover 120 or the bottom wall 111 where the notched groove 102 is located to be deformed due to heat, gradually reducing the width of the notched groove 102 toward the interior of the shell 100 can also reduce the possibility of the shell cover 120 or the bottom wall 111 where the notched groove 102 is deformed due to heat.
  • the cross section of the notch groove 102 may be in the shape of an inverted trapezoid.
  • the cross-section of the notched groove 102 may also be in a V-shape, a U-shape, or the like.
  • the cross section of the notched groove 102 is a cross section of the notched groove 102 in a direction perpendicular to its extending direction.
  • the maximum width of the notch groove 102 is W, which satisfies 0.02 mm ⁇ W ⁇ 0.5 mm.
  • W can be 0.02 mm, 0.2 mm, or 0.5 mm.
  • the notched groove 102 By setting the maximum width W of the notched groove 102 to 0.02 mm to 0.5 mm, the notched groove 102 can be easily broken when the pressure inside the housing 100 is high, and the pressure relief reliability is high. In addition, the cost of the notched groove 102 is low, and the notched groove 102 is not easy to be broken.
  • the electrochemical device 10 may break when dropped or subjected to external force.
  • 0.05 mm ⁇ W ⁇ 0.2 mm In some embodiments, 0.05 mm ⁇ W ⁇ 0.2 mm.
  • W may be 0.05 mm, 0.1 mm, or 0.2 mm.
  • the notch groove 102 can be easily broken when the pressure inside the housing 100 is high, and the pressure relief reliability is high. In addition, the cost of the notch groove 102 is low, and the notch groove 102 is not likely to break when the electrochemical device 10 falls or is subjected to external force.
  • 0.06 mm ⁇ W ⁇ 0.18 mm 0.06 mm ⁇ W ⁇ 0.18 mm.
  • W may be 0.06 mm, 0.12 mm, or 0.18 mm.
  • the maximum width W of the notched groove 102 By setting the maximum width W of the notched groove 102 to 0.06 mm to 0.18 mm, it is possible to further make the notched groove 102 easy to rupture when the pressure inside the shell 100 is high, and the pressure relief reliability is high. In addition, the cost of the notched groove 102 is low, and the notched groove 102 is not easy to rupture when the electrochemical device 10 falls or is subjected to external force.
  • the hot melt pressure relief (pressure relief mechanism 200) of the present scheme with the notched groove 102 in the shell 100 of the same electrochemical device 10, it is possible to set the maximum width W of the notched groove 102 to 0.06 to 0.18 mm.
  • the thickness S2 of the second wall satisfies 0.03 mm ⁇ S2 ⁇ 0.3 mm.
  • S2 may be 0.03 mm, 0.2 mm, or 0.3 mm.
  • the second wall is not easily deformed by force or heat, and the second wall occupies a smaller space, which is beneficial to improving the energy density of the electrochemical device 10 .
  • Table 1 is a comparison of the hot box test pass rate and drop test pass rate of multiple embodiments of the electrochemical device currently provided with only the notched groove and multiple embodiments of the electrochemical device provided with the notched groove and the pressure relief mechanism in the present application.
  • the experiment was conducted by taking the notched groove 102 provided on the shell cover 120 as an example.
  • S1 is the depth of the notched groove 102
  • S2 is the thickness of the shell cover 120 where the notched groove 102 is located
  • W is the maximum width of the notched groove 102.
  • the units of the depth of the notched groove 102, the thickness of the shell cover 120, and the maximum width of the notched groove 102 are all in mm.
  • the method of hot box testing is as follows:
  • the oven temperature is increased from an initial temperature of 23 ⁇ 2°C at a rate of 5 ⁇ 2°C/min until the oven temperature reaches 130 ⁇ 2°C, and then the oven temperature is maintained at 130 ⁇ 2°C for 60 minutes.
  • the method of drop test is as follows:
  • the six surfaces and four corners of the electrochemical device are directed downward and are allowed to freely fall from a height of 1.5 meters onto a concrete surface, where the height refers to the distance from the lowest point of the electrochemical device to the concrete surface.
  • the OCV of the electrochemical device is tested to see whether it is greater than or equal to 90% of the initial OCV value before the drop.
  • the electrochemical device is provided with a pressure relief mechanism and a notch groove for pressure relief.
  • the maximum width W of the notch groove is 0.2 mm and the depth S1 of the notch groove is 0.01-0.05 mm, the greater the depth S1 of the notch groove, the greater the pass rate of the hot box test, and the pass rate of the drop test is also higher.
  • the electrochemical device is provided with a pressure relief mechanism and a notched groove for pressure relief.
  • the maximum width W of the notched groove is 0.2 mm and the depth S1 of the notched groove is 0.07-0.095 mm, the greater the depth S1 of the notched groove, the lower the drop test pass rate, and the higher the hot box test pass rate.
  • the maximum width of the notched groove of the electrochemical device that only has a notched groove for pressure relief is 0.05-0.5 mm
  • the maximum width of the notched groove of the electrochemical device that has a pressure relief mechanism and a notched groove in the present application is 0.02 mm, which can reduce the cost of the notched groove, improve the pass rate of the hot box test, and do not reduce the pass rate of the drop test.
  • the electrochemical device in the present application has a pressure relief mechanism and notched grooves for pressure relief, which can improve the pass rate of the hot box test, and the pass rate of the drop test is not reduced.
  • the present application also provides an electrical device, including the electrochemical device 10 provided in any of the above embodiments, and the electrochemical device 10 is used to provide electrical energy.
  • the electrical device may be any of the aforementioned devices or equipment using the electrochemical device 10 .

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Abstract

一种电化学装置(10)及用电设备,该电化学装置(10)包括外壳(100)和泄压机构(200),外壳(100)的第一壁体设置有第一通孔(101),泄压机构(200)覆盖第一通孔(101),泄压机构(200)包括胶膜(210),胶膜(210)能够受热熔融或失粘以形成第一泄压通道,外壳(100)的第二壁体上设置有刻痕槽(102),刻痕槽(102)能够在外壳(100)的内部压力达到阈值时破裂,以形成第二泄压通道,使得电化学装置(10)能够形成两条泄压通道,能够提高电化学装置(10)的泄压灵敏度和泄压的可靠性,减小电化学装置(10)热失控的概率;刻痕槽(102)的深度S1和第二壁体的厚度S2满足0.1*S2≤S1≤0.95*S2,并且由于电化学装置(10)通过多通道泄压,因此将刻痕槽(102)的深度S1设置在上述范围能够实现较快的泄压响应,且不易破裂。

Description

电化学装置及用电设备
相关申请的交叉引用
本申请要求享有于2023年11月15日提交的名称为“电化学装置及用电设备”中国专利申请CN202311517153.9的优先权,该申请的全部内容通过引用并入本文中。
技术领域
本申请涉及电池技术领域,具体而言,涉及一种电化学装置及用电设备。
背景技术
随着新能源技术的快速发展,电池已经被广泛应用于电子设备、电动汽车、电动两轮车、电动工具等领域。对电池的质量及安全等要求也越来越高。
目前,电化学装置的外壳上设置有刻痕槽,能够在电化学装置的内部压力过大时破裂,以形成泄压通道,对电化学装置进行泄压。而刻痕槽的热灵敏性较差,造成泄压的可靠性较差,热失控的概率较大。
发明内容
本申请提供一种电化学装置及用电设备,能够有效提高电化学装置的泄压灵敏度。
第一方面,本申请提供一种电化学装置,包括:
外壳,包括第一壁体和第二壁体,第一壁体设置有第一通孔;
泄压机构,覆盖所述第一通孔,所述泄压机构包括胶膜,所述胶膜能够受热熔融或失粘以形成连通所述外壳内部和外部的第一泄压通道;
所述第二壁体上设置有刻痕槽,所述刻痕槽能够在所述外壳的内部压力达到阈值时破裂,以形成连通所述外壳内部和外部的第二泄压通道;
所述刻痕槽的深度为S1,所述第二壁体的厚度为S2,满足0.1*S2≤S1≤0.95*S2。
在上述技术方案中,电化学装置包括外壳及泄压机构,外壳包括第一壁体和第二壁体,泄压机构覆盖第一壁体的第一通孔,泄压机构包括胶膜,胶膜能够受热熔融或失粘以形成连通外壳内部和外部的第一泄压通道,外壳上还设置有刻痕槽,刻痕槽能够在外壳的内部压力达到阈值时破裂,以形成连通外壳内部和外部的第二泄压通道,即在电化学装置的温度较高时,能够形成第一泄压通道,在电化学装置的内部压力较高时,能够形成第二泄压通道,从而使得电化学装置能够形成两条泄压通道,电化学装置在发生安全风险时,主要有两种现象:发热及产气,泄压机构可以有效感知电化学装置的发热,达到熔点时产生泄压。而当电化学装置出现一些产热较少、产气较多的工况如过放的情况,电化学装置内部产热较少,产气量较大,因此需要泄压,但泄压机构对温度较为敏感,可能会导致无法及时泄压,而刻痕槽可以有效感知电化学装置产气,产气量达到一定程度时,外壳气胀变形,刻痕槽开启,上述方案可以适应不同的情况,能够提高电化学装置的泄压灵敏度和泄压的可靠性,减小电化学装置热失控的概率。通过使得刻痕槽的深度S1,第二壁体的厚度S2满足0.1*S2≤S1≤0.95*S2,能够使得外壳内部的压力较大时,刻痕槽容易破裂,泄压可靠性较高,并且刻痕槽的成本较低,刻痕槽不易在电化学装置跌落或受外力作用时破裂;当刻痕槽较深时,泄压响应快,但太深容易造成破裂,当刻痕槽较浅时,不容易破裂,但泄压响应较慢;通过上述技术方案,限定刻痕槽深度能够平衡二者之间的关系,并且由于本方案为泄压机构与刻痕槽共同的作用,因此能够将刻痕槽深度做的更小也不会出现泄压响应缓慢的问题;在电化学装置中如果仅设置单一刻痕槽泄压功能,因为刻痕槽泄压灵敏度低,需要将刻痕槽加深,但刻痕槽较深时存在滚筒、跌落漏液的问题,且刻痕槽成本高,本方案通过多通道的泄压结构,因此能够将刻痕槽的深度限定到上述范围之内。
在第一方面的一些实施例中,0.4*S2≤S1≤0.8*S2。
在上述技术方案中,通过使得刻痕槽的深度S1,第二壁体的厚度S2满足0.4*S2≤S1≤0.8*S2,能够进一步使得外壳内部的压力较大时,刻痕槽容易破裂,泄压可靠性较高,并且刻痕槽的成本较低,刻痕槽不易在电化学装置跌落或受外力作用时破裂。
在第一方面的一些实施例中,0.55*S2≤S1≤0.8*S2。
在上述技术方案中,通过使得刻痕槽的深度S1,第二壁体的厚度S2满足0.55*S2≤S1≤0.8*S2,能够进一步使得外壳内部的压力较大时,刻痕槽容易破裂,泄压可靠性较高,并且刻痕槽的成本较低,刻痕槽不易在电化学装置跌落或受外力作用时破裂,通过将本方案的热熔泄压(泄压机构)与刻痕槽集成于同一电化学装置的外壳,能够实现将刻痕槽的深度S1和第二壁体的厚度S2满足0.55*S2≤S1≤0.8*S2。
在第一方面的一些实施例中,所述泄压机构还包括第一金属片,所述第一金属片设置于所述胶膜背向所述外壳的一侧。
在上述技术方案中,通过在胶膜背向壳体的一侧设置第一金属片,能够减小胶膜的渗水面积,使得泄压机构的密封效果更好。
在第一方面的一些实施例中,所述第一金属片呈圆形设置,所述胶膜呈圆形或圆环形设置,所述第一通孔呈圆形设置,所述第一金属片的直径小于或等于所述胶膜的外径,所述第一金属片的直径大于或等于所述第一通孔的直径。
在上述技术方案中,通过将第一金属片设置成圆形,将胶膜设置成圆形或圆环形设置,将第一通孔设置成圆形,并使得第一金属片的直径小于或等于胶膜的外径,使得第一金属片的直径大于或等于第一通孔的直径,能够便于胶膜、第一金属片与外壳装配,且第一金属片能够覆盖第一通孔,减小水汽经胶膜、第一通孔渗入外壳内部的可能性,使得泄压机构的密封效果更好。
在第一方面的一些实施例中,所述泄压机构还包括第二金属片,所述第二金属片设置于所述胶膜和所述外壳之间,所述第二金属片与所述外壳焊接,所述第二金属片设置有第二通孔。
在上述技术方案中,通过设置第二金属片以与外壳焊接,能够使得泄压机构与外壳的连接更加稳定,密封效果更好。
在第一方面的一些实施例中,所述第一金属片呈圆形设置,所述第一通孔呈圆形设置,所述第二金属片呈圆环形设置,所述第二金属片的外径大于或等于所述第一通孔的直径,所述第一金属片的直径小于或等于所述第二金属片的外径,所述第一金属片的直径大于或等于所述第二金属片的内径。
在上述技术方案中,通过将第一金属片设置成圆形,将第一通孔设置成圆形,将第二金属片设置成圆环形,并使得第二金属片的外径大于或等于第一通孔的直径,便于第二金属片与外壳焊接;第一金属片的直径小于或等于第二金属片的外径,能够减小第一金属片遮挡第二金属片与外壳焊接的可能;第一金属片的直径大于或等于第二金属片的内径,使得第一金属片能够覆盖第二通孔,减小水汽经胶膜、第二通孔渗入外壳内部的可能性,使得泄压机构的密封效果更好。
在第一方面的一些实施例中,所述第一通孔呈圆形设置,所述第一通孔的直径为D1,所述第二金属片呈圆环形设置,所述第二金属片的外径为D2,所述第二金属片的内径为D3,满足0.2mm≤D1≤5mm,1mm≤D2≤6mm,0.1mm≤D3≤3mm。
在上述技术方案中,通过将第一通孔的直径D1设置在0.2mm至5mm,能够使得电化学装置在热失控时,第一通孔能够提供截面积较大的第一泄压通道,且无需较大尺寸的泄压机构覆盖第一通孔,便于泄压机构的安装;通过将第二金属片的外径D2设置在1mm至6mm,使得第二金属片有足够的面积与外壳贴合,能够便于第二金属片与外壳的焊接,且第二金属片不会超出外壳,成本较低;通过将第二金属片的内径D3设置在0.1mm至3mm,使得通过第二通孔形成第一泄压通道时,第二通孔能够提供截面积较大的第一泄压通道,且无需较大尺寸的胶膜和第一金属片覆盖第二通孔,便于胶膜和第一金属片的安装。
在第一方面的一些实施例中,所述第一金属片的厚度为H1,所述第二金属片的厚度为H2,满足0.03mm≤H1≤1mm,0.03mm≤H2≤1mm。
在上述技术方案中,通过将第一金属片的厚度H1设置在0.03mm至1mm,将第二金属片的厚度H2设置在0.03mm至1mm,使得第一金属片和第二金属片的密封效果更好,减小水汽渗入外壳内部的可能性,并且能够使得泄压机构的厚度较小,从而使得泄压机构在电化学装置的长度方向上占用的空间较小,有利于提高电化学装置的能量密度。
在第一方面的一些实施例中,所述胶膜的熔点为T,满足95℃≤T≤135℃。
在上述技术方案中,通过将胶膜的熔点T设置在95℃至135℃,能够使得胶膜对第一通孔的密封可靠性较高,且电化学装置在热失控时,胶膜能够熔融或失粘以形成第一泄压通道,使得电化学装置的泄压灵敏性较高。
在第一方面的一些实施例中,所述胶膜包括第一胶层和第二胶层,所述第一胶层与所述第 二胶层层叠设置,所述第二胶层位于所述第一胶层背向所述外壳的一侧,所述第一胶层的熔点小于所述第二胶层的熔点。
在上述技术方案中,通过设置第一胶层和第二胶层,并且使得第一胶层的熔点小于第二胶层的熔点,能够使得胶膜被高温激活时,第一胶层能够熔融以与外壳贴合,同时第二胶层不会熔融,能够避免胶膜过熔融而影响胶膜的安装,还能够减少胶膜的溢胶量。
在第一方面的一些实施例中,所述第一胶层的熔点为T1,所述第二胶层的熔点为T2,满足95℃≤T1≤135℃,140℃≤T2≤190℃。
在上述技术方案中,通过将第一胶层的熔点T1设置在95℃至135℃,将第二胶层的熔点T2设置在140℃至190℃,能够使得胶膜对第一通孔的密封可靠性较高,且第一胶层能够先于第二胶层熔融,便于在胶膜被高温激活时安装于外壳;电化学装置在热失控时,第一胶层能够比第二胶层先熔融或失粘以形成第一泄压通道,使得电化学装置的泄压灵敏性较高,且能够减少胶膜的溢胶量。
在第一方面的一些实施例中,所述泄压机构还包括第一金属片,所述第一金属片设置于所述胶膜背向所述外壳的一侧,所述胶膜还包括第三胶层,所述第三胶层位于所述第二胶层和所述第一金属片之间,所述第三胶层的熔点小于所述第二胶层的熔点。
在上述技术方案中,通过设置第三胶层,并使得第三胶层的熔点小于第二胶层的熔点,能够使得胶膜被高温激活时,第三胶层能够熔融以与第一金属片贴合,同时第二胶层不会熔融,能够避免胶膜过熔融而影响第一金属片的安装,还能够减少溢胶量;电化学装置在热失控时,第一胶层与外壳之间、第三胶层与第一金属片之间都能够熔融或失粘以形成第一泄压通道,提高电化学装置的泄压灵敏性、泄压的可靠性,减小电化学装置热失控的概率。
在第一方面的一些实施例中,所述第三胶层的熔点为T3,满足95℃≤T3≤135℃。
在上述技术方案中,通过将第三胶层的熔点T3设置在95℃至135℃,能够使得胶膜对第一通孔的密封可靠性较高,且第三胶层能够先于第二胶层熔融或失粘,便于在胶膜被高温激活时安装于第一金属片;电化学装置在热失控时,第三胶层能够比第二胶层先熔融或失粘以形成第一泄压通道,使得电化学装置的泄压灵敏性较高。
在第一方面的一些实施例中,所述外壳设置有凹槽,所述第一通孔贯穿所述凹槽,所述泄压机构容置于所述凹槽内。
在上述技术方案中,通过在外壳设置凹槽,并使得第一通孔贯穿凹槽,泄压机构容置于凹槽内,使得泄压机构超出外壳的外表面的部分的厚度较小,或者泄压机构不超出外壳的外表面,从而能够减小泄压机构与其他部件干涉而受损或脱离外壳的可能性。
在第一方面的一些实施例中,所述第一通孔呈跑道形、长方形或椭圆形设置。
在上述技术方案中,通过使得第一通孔呈跑道形、长方形或椭圆形设置,能够使得电化学装置的厚度较小时,第一通孔的面积较大,泄压可靠性较高。
在第一方面的一些实施例中,所述外壳包括壳体和壳盖,所述壳体包括底壁和围设于所述底壁的多个侧壁,所述底壁和多个所述侧壁共同围成具有开口的容纳空间,所述壳盖封闭所述开口,所述侧壁为所述第一壁体,所述底壁或所述壳盖为所述第二壁体。
在上述技术方案中,通过将第一通孔设置于壳体的侧壁,能够减小第一泄压通道被阻挡的可能,泄压机构的泄压可靠性较高;通过将刻痕槽设置于壳体的底壁或壳盖,能够形成尺寸较大的第二泄压通道,便于外壳内部的气体快速排出,泄压可靠性较高。
在第一方面的一些实施例中,所述电化学装置还包括极柱,所述极柱和所述第一通孔设置于同一个所述侧壁。
在上述技术方案中,在电化学装置设置极柱的一侧,电极组件和外壳之间形成有间隔空间,通过将极柱和第一通孔设置于同一个侧壁,能够便于外壳内部的气体经间隔空间、第一通孔排出,泄压可靠性较高;并且由于电化学装置被装入用电设备时,需要预留空间以便于极柱与用电设备的其他装置电连接,因此将极柱和第一通孔设置于同一个侧壁,无需再另外为泄压机构预留空间以实现泄压,能够节省用电设备的空间,使得用电设备的结构更加紧凑。
在第一方面的一些实施例中,所述电化学装置还包括极柱,所述极柱和所述第一通孔设置于不同的所述侧壁。
在上述技术方案中,由于极柱能够用于与电路板进行连接,通过将极柱和第一通孔设置于不同的侧壁,能够使得泄压机构形成第一泄压通道后,电化学装置内部的电解液不易经第一泄压通 道喷溅至电路板上,从而能够减小电解液造成电路板上的元器件短路的可能性。
在第一方面的一些实施例中,所述刻痕槽靠近所述外壳的边角设置。
在上述技术方案中,由于外壳的边角为外壳的应力集中区域,因此通过将刻痕槽设置在外壳的边角,能够使得外壳内部的压力较大时,刻痕槽更容易破裂,泄压可靠性更高。
在第一方面的一些实施例中,所述电化学装置还包括极柱,所述极柱设置于所述外壳,所述刻痕槽靠近所述外壳设置有所述极柱的一端。
在上述技术方案中,在电化学装置设置极柱的一侧,电极组件和外壳之间形成有间隔空间,通过使得刻痕槽靠近外壳设置有极柱的一端,能够便于外壳内部的气体经间隔空间、刻痕槽破裂形成的泄压口排出,泄压可靠性较高。
在第一方面的一些实施例中,所述刻痕槽呈弧形设置,且朝向所述刻痕槽所在的所述壳盖或所述底壁的中心弯曲。
在上述技术方案中,通过将刻痕槽设置成弧形,且使得刻痕槽朝向刻痕槽所在的壳盖或所述底壁的中心弯曲,能够便于刻痕槽的加工成型,并且外壳内部的压力较大时,壳盖或底壁的中部受力较大,因此刻痕槽更容易破裂并形成较大的泄压口,便于外壳内部的气体快速排出,泄压可靠性较高。
在第一方面的一些实施例中,所述刻痕槽的宽度向靠近所述外壳内部的方向逐渐减小。
在上述技术方案中,通过使得刻痕槽的宽度向靠近外壳内部的方向逐渐减小,能够减少刻痕槽的加工成本,且能够减少刻痕槽所在的壳盖或底壁受热变形的可能性。
在第一方面的一些实施例中,所述刻痕槽的最大宽度为W,满足0.02mm≤W≤0.5mm。
在上述技术方案中,通过将刻痕槽的最大宽度W设置在0.02mm至0.5mm,能够使得外壳内部的压力较大时,刻痕槽容易破裂,泄压可靠性较高,并且刻痕槽的成本较低,刻痕槽不易在电化学装置跌落或受外力作用时破裂。
在第一方面的一些实施例中,0.05mm≤W≤0.2mm。
在上述技术方案中,通过将刻痕槽的最大宽度W设置在0.05mm至0.2mm,能够进一步使得外壳内部的压力较大时,刻痕槽容易破裂,泄压可靠性较高,并且刻痕槽的成本较低,刻痕槽不易在电化学装置跌落或受外力作用时破裂。
在第一方面的一些实施例中,0.06mm≤W≤0.18mm。
在上述技术方案中,通过将刻痕槽的最大宽度W设置在0.06mm至0.18mm,能够进一步使得外壳内部的压力较大时,刻痕槽容易破裂,泄压可靠性较高,并且刻痕槽的成本较低,刻痕槽不易在电化学装置跌落或受外力作用时破裂,通过将本方案的热熔泄压(泄压机构)与刻痕槽集成于同一电化学装置的外壳,能够实现将刻痕槽的最大宽度W设置在0.06至0.18mm。
在第一方面的一些实施例中,第二壁体的厚度S2满足0.03mm≤S2≤0.3mm。
在上述技术方案中,通过将第二壁体S2设置为0.03mm至0.3mm,能够使得第二壁体不易受力或受热变形,且第二壁体占用的空间较小,有利于提高电化学装置的能量密度。
第二方面,本申请提供一种用电设备,包括如上述的电化学装置,所述电化学装置用于提供电能。
附图说明
为了更清楚地说明本申请实施例的技术方案,下面将对实施例中所需要使用的附图作简单地介绍,应当理解,以下附图仅示出了本申请的某些实施例,因此不应被看作是对范围的限定,对于本领域普通技术人员来讲,还可以根据这些附图获得其他相关的附图。
图1为本申请一些实施例提供的电化学装置的立体结构示意图;
图2为本申请一些实施例提供的电化学装置的爆炸结构示意图;
图3为本申请一些实施例提供的电化学装置的剖视结构示意图;
图4为图3所示的电化学装置的A处的局部放大结构示意图;
图5为本申请一些实施例提供的电化学装置的部分结构的一个视角的结构示意图;
图6为本申请另一些实施例提供的电化学装置的立体结构示意图;
图7为图6实施例提供的电化学装置的部分结构的剖视示意图;
图8为本申请另一些实施例提供的电化学装置的立体结构示意图;
图9为图8实施例提供的电化学装置的部分结构的剖视示意图;
图10为本申请一些实施例提供的电化学装置的胶膜的一个视角的结构示意图;
图11为本申请一些实施例提供的电化学装置的胶膜的另一个视角的剖视结构示意图;
图12为本申请一些实施例提供的电化学装置的一个视角的结构示意图;
图13为本申请一些实施例提供的电化学装置的另一个视角的剖视结构示意图;
图14为图13所示的电化学装置的B处的局部放大结构示意图。
图标:10-电化学装置;100-外壳;101-第一通孔;102-刻痕槽;110-壳体;111-底壁;112-第一侧壁;113-第二侧壁;114-第三侧壁;115-第四侧壁;120-壳盖;200-泄压机构;210-胶膜;211-第一胶层;212-第二胶层;213-第三胶层;220-第一金属片;230-第二金属片;231-第二通孔;300-极柱;400-电极组件。
具体实施例方式
为使本申请的目的、技术方案和优点更加清楚,下面将结合本申请实施例中的附图,对本申请实施例中的技术方案进行清楚地描述,显然,所描述的实施例是本申请一部分实施例,而不是全部的实施例。基于本申请中的实施例,本领域普通技术人员所获得的所有其他实施例,都属于本申请保护的范围。
除非另有定义,本申请所使用的所有的技术和科学术语与属于本申请的技术领域的技术人员通常理解的含义相同;在本申请的说明书中所使用的术语只是为了描述具体的实施例的目的,不是旨在于限制本申请;本申请的说明书和权利要求书及上述附图说明中的术语“包括”和“具有”以及它们的任何变形,意图在于覆盖不排他的包含。
本申请的说明书和权利要求书或上述附图中的术语“第一”、“第二”等是用于区别不同对象,而不是用于描述特定顺序或主次关系。
在本申请中提及“实施例”意味着,结合实施例描述的特定特征、结构或特性可以包含在本申请的至少一个实施例中。在说明书中的各个位置出现该短语并不一定均是指相同的实施例,也不是与其它实施例互斥的独立的或备选的实施例。
在本申请的实施例中,相同的附图标记表示相同的部件,并且为了简洁,在不同实施例中,省略对相同部件的详细说明。应理解,附图示出的本申请实施例中的各种部件的厚度、长宽等尺寸,以及集成装置的整体厚度、长宽等尺寸仅为示例性说明,而不应对本申请构成任何限定。
本申请中,电化学装置可以为二次电池或一次电池;例如电化学装置可以是锂离子电池、钠离子电池或镁离子电池等,本申请实施例对此并不限定。电化学装置可呈圆柱体、扁平体、长方体或其它形状等,本申请实施例对此也不限定。电极组件可以是卷绕式结构,也可以是叠片式结构,本申请实施例并不作限定。
随着新能源行业的发展,对电池的质量及安全等要求也越来越高。电化学装置具有能量密度高、环境污染小、功率密度大、使用寿命长、适应范围广、自放电系数小等突出的优点,是现今新能源发展的重要组成部分。
目前的电化学装置主要是通过在壳盖上进行激光刻槽,以形成刻痕槽,以在电化学装置的内部气压过大时,使得刻痕槽能够破裂,以形成泄压通道,将电芯内部的气体排出,起到防爆的作用。但是刻痕槽主要是靠电化学装置内部的气压作用以产生破裂,热灵敏性较差,热盒测试的通过率较低,在电化学装置的温度较高而气压未达到预设值时,刻痕槽产生破裂的概率较低,仍存在电化学装置热失控的风险。
基于上述考虑,为了解决目前电化学装置的泄压灵敏度较低的问题,本申请提供了一种电化学装置,电化学装置包括外壳和泄压机构,外壳包括第一壁体和第二壁体,第一壁体设置有第一通孔,泄压机构覆盖第一通孔,泄压机构包括胶膜,胶膜能够受热熔融或失粘以形成连通外壳内部和外部的第一泄压通道,第二壁体上设置有刻痕槽,刻痕槽能够在外壳的内部压力达到阈值时破裂,以形成连通外壳内部和外部的第二泄压通道;刻痕槽的深度为S1,第二壁体的厚度为S2,满足0.1*S2≤S1≤0.95*S2。在电化学装置的温度较高时,能够形成第一泄压通道,在电化学装置的内部压力较高时,能够形成第二泄压通道,从而使得电化学装置能够形成两条泄压通道,以适应不同的情况,能够提高电化学装置的泄压灵敏度和泄压的可靠性,减小电化学装置热失控的概率。并且通过使得0.1*S2≤S1≤0.95*S2,能够使得外壳内部的压力较大时,刻痕槽容易破裂,泄压可靠性较高,并且刻痕槽的成本较低,刻痕槽不易在电化学装置跌落或受外力作用时破裂;当刻痕槽较深时,泄压响应快,但太深容易造成破裂,当刻痕槽较浅时,不容易破裂,但泄压响应较慢;通过 上述技术方案,限定刻痕槽深度能够平衡二者之间的关系,并且由于本方案为泄压机构与刻痕槽共同的作用,因此能够将刻痕槽深度做的更小也不会出现泄压响应缓慢的问题。
本申请实施例提供一种使用电化学装置作为电源的用电设备,用电设备可以为但不限于手机、平板、笔记本电脑、电动玩具、电动工具、电瓶车、电动汽车、轮船、航天器等等。其中,电动玩具可以包括固定式或移动式的电动玩具,例如,游戏机、电动汽车玩具、电动轮船玩具和电动飞机玩具等等,航天器可以包括飞机、火箭、航天飞机和宇宙飞船等等。
本申请的实施例描述的电化学装置不仅仅局限适用于上述所描述的用电设备,还可以适用于所有使用电化学装置的用电设备。
参见图1和图2,图1为本申请一些实施例提供的电化学装置的立体结构示意图,图2为本申请一些实施例提供的电化学装置的爆炸结构示意图。电化学装置10包括外壳100、极柱300以及电极组件400,外壳100形成有容纳空间,容纳空间用于容置电极组件400和电解液,极柱300贯穿外壳100设置,且与电极组件400电连接。电极组件400由正极极片、负极极片和隔离膜组成,正极极片包括正极集流体和正极活性物质层,正极活性物质层涂覆于正极集流体的表面。以锂离子电池为例,正极集流体的材料可以为铝,正极活性物质可以为钴酸锂、磷酸铁锂、三元锂或锰酸锂等。负极极片包括负极集流体和负极活性物质层,负极活性物质层涂覆于负极集流体的表面。负极集流体的材料可以为铜,负极活性物质可以为碳或硅等。电化学装置10主要依靠金属离子在正极极片和负极极片之间移动来工作。在电化学装置10工作过程中,电化学装置10的温度会升高,且电极组件400可能会产生气体,使得外壳100内部的压力升高。外壳100内部的压力不断累积增大,可能会产生爆炸,而电化学装置10温度过高会造成热失控,进而可能造成电化学装置10损坏。
在本申请的一些实施例中,电化学装置10包括外壳100和泄压机构200,外壳100包括第一壁体和第二壁体,第一壁体设置有第一通孔101。泄压机构200覆盖第一通孔101,泄压机构200包括胶膜210,胶膜210能够受热熔融或失粘以形成连通外壳100内部和外部的第一泄压通道。第二壁体上设置有刻痕槽102,刻痕槽102能够在外壳100的内部压力达到阈值时破裂,以形成连通外壳100内部和外部的第二泄压通道。刻痕槽102的深度为S1,第二壁体的厚度为S2,满足0.1*S2≤S1≤0.95*S2。例如S1可以为0.1*S2、0.5*S2或0.95*S2等。
在一些实施例中,刻痕槽102可以通过激光蚀刻的方式形成。
通过设置泄压机构200,使得泄压机构200覆盖第一壁体的第一通孔101,且泄压机构200包括胶膜210,胶膜210能够受热熔融或失粘以形成连通外壳100内部和外部的第一泄压通道,第二壁体上还设置有刻痕槽102,刻痕槽102能够在外壳100的内部压力达到阈值时破裂,以形成连通外壳100内部和外部的第二泄压通道,即在电化学装置10的温度较高时,能够形成第一泄压通道,在电化学装置10的内部压力较高时,能够形成第二泄压通道,从而使得电化学装置10能够形成两条泄压通道,电化学装置10在发生安全风险时,主要有两种现象:发热及产气,泄压机构200可以有效感知电化学装置10的发热,达到熔点时产生泄压。而当电化学装置10出现一些产热较少、产气较多的工况如过放电的情况,电化学装置10内部产热较少,产气量较大,因此需要泄压,但泄压机构200对温度较为敏感,可能会导致无法及时泄压,而刻痕槽102可以有效感知电化学装置10产气,产气量达到一定程度时,外壳气胀变形,刻痕槽102开启,上述方案可以适应不同的情况,能够提高电化学装置10的泄压灵敏度和泄压的可靠性,减小电化学装置10热失控的概率。通过使得刻痕槽102的深度S1,第二壁体的厚度S2满足0.1*S2≤S1≤0.95*S2,能够使得外壳100内部的压力较大时,刻痕槽102容易破裂,泄压可靠性较高,并且刻痕槽102的成本较低,刻痕槽102不易在电化学装置10跌落或受外力作用时破裂;当刻痕槽102较深时,泄压响应快,但太深容易造成破裂,当刻痕槽102较浅时,不容易破裂,但泄压响应较慢。通过上述技术方案,限定刻痕槽102的深度能够平衡二者之间的关系,并且由于本方案为泄压机构200与刻痕槽102共同的作用,因此能够将刻痕槽102深度做的更小也不会出现泄压响应缓慢的问题;在电化学装置10中如果仅设置单一刻痕槽102泄压功能,因为刻痕槽102泄压灵敏度低,需要将刻痕槽102加深,但刻痕槽102较深时存在滚筒、跌落漏液的问题,且刻痕槽102成本高,本方案通过多通道的泄压结构,因此能够将刻痕槽102的深度限定到上述范围之内。
在外壳100的内部压力较大时,泄压机构200也可以在压力作用下形成第一泄压通道,从而加快气体的排出。
在一些实施例中,第一通孔101可以为注液孔,经由第一通孔101向电化学装置10内部 注入电解液。
通过复用注液孔作为用于泄压的第一通孔101,能够进一步简化电化学装置10的制备过程,减少打孔步骤,降低电化学装置10的制备成本。
在另一些实施例中,第一通孔101也可以为形成于外壳100的其他通孔。
在一些实施例中,0.4*S2≤S1≤0.8*S2。例如S1可以为0.4*S2、0.6*S2或0.8*S2等。
通过使得刻痕槽102的深度S1,第二壁体的厚度S2满足0.4*S2≤S1≤0.8*S2,能够进一步使得外壳100内部的压力较大时,刻痕槽102容易破裂,泄压可靠性较高,并且刻痕槽102的成本较低,刻痕槽102不易在电化学装置10跌落或受外力作用时破裂。
在一些实施例中,0.55*S2≤S1≤0.8*S2。例如S1可以为0.55*S2、0.65*S2或0.8*S2等。
通过使得刻痕槽102的深度S1,第二壁体的厚度S2满足0.55*S2≤S1≤0.8*S2,能够进一步使得外壳100内部的压力较大时,刻痕槽102容易破裂,泄压可靠性较高,并且刻痕槽102的成本较低,刻痕槽102不易在电化学装置10跌落或受外力作用时破裂,通过将本方案的热熔泄压(泄压机构200)与刻痕槽102集成于同一电化学装置10的外壳,能够实现将刻痕槽102的深度S1和第二壁体的厚度S2满足0.55*S2≤S1≤0.8*S2。
在一些实施例中,泄压机构200还可以包括第一金属片220,第一金属片220设置于胶膜210背向外壳100的一侧。
在一些实施例中,第一金属片220沿胶膜210的厚度方向与胶膜210层叠设置。由于胶膜210为高分子聚合物,具有透水性,而水分经胶膜210进入外壳100内部后,会对电极组件400及电解液产生不良影响,通过在胶膜210背向外壳100的一侧设置第一金属片220,使得第一金属片220能够覆盖胶膜210的至少部分,能够减小胶膜210的渗水面积,使得密封效果更好,进而使得电化学装置10的使用寿命更长。
在一些实施例中,胶膜210可以为高分子聚合物制成,例如聚丙烯(PP,Polypropylene),韧性较好,耐化学性较好。
在一些实施例中,第一金属片220可以为铝、镍、不锈钢等材料制成,不易生锈,使用寿命较长。
一并参见图3至图5,图3为本申请一些实施例提供的电化学装置的剖视结构示意图,图4为图3所示的电化学装置的A处的局部放大结构示意图;图5为本申请一些实施例提供的电化学装置的部分结构的一个视角的结构示意图。
在一些实施例中,第一金属片220呈圆形设置,胶膜210呈圆形设置,第一通孔101呈圆形设置,第一金属片220的直径D4小于或等于胶膜210的外径D2,第一金属片220的直径D4大于或等于第一通孔101的直径D1。
通过将第一金属片220设置成圆形,无需调整第一金属片220的装配方向,能够便于第一金属片220与胶膜210转配。通过将胶膜210设置成圆形设置,将第一通孔101设置成圆形,无需调整胶膜210的装配方向,能够便于胶膜210与外壳100装配,且胶膜210的轴线与第一通孔101的轴线共线时,胶膜210与外壳100的贴合面分布均匀,密封效果更好。通过使得第一金属片220的直径D4小于或等于胶膜210的外径D2,能够在第一金属片220、胶膜210与外壳100装配时,减小第一金属片220遮挡胶膜210的可能性,便于胶膜210在外壳100上的定位,使得胶膜210覆盖第一通孔101,从而便于胶膜210、第一金属片220与外壳100装配,且泄压机构200与外壳100的密封更好。通过使得第一金属片220的直径D4大于或等于第一通孔101的直径D1,使得第一金属片220能够覆盖第一通孔101,减小水汽经胶膜210、第一通孔101渗入外壳100内部的可能性,使得泄压机构200的密封效果更好。
在另一些实施例中,第一通孔101可以呈跑道形、长方形或椭圆形设置。
通过使得第一通孔101呈跑道形、长方形或椭圆形设置,能够使得电化学装置10的厚度较小时,第一通孔101的面积较大,泄压可靠性较高。
在另一些实施例中,第一金属片220也可以呈椭圆形、方形等形状设置。胶膜210也可以呈椭圆形、方形等形状设置。
在另一些实施例中,胶膜210还可以呈圆环形设置,无需调整胶膜210的装配方向,能够便于胶膜210与外壳100装配,胶膜210的轴线与第一通孔101的轴线共线时,胶膜210与外壳100的贴合面分布均匀,密封效果更好。并且胶膜210受热熔融或失粘时,胶膜210与外壳100之间、胶膜210与第一金属片220之间都可以形成第一泄压通道,能够增加第一泄压通道的数量,使 得泄压灵敏度更高,泄压效果更好。
在另一些实施例中,胶膜210也可以呈椭圆环形、方环形等形状设置。
参见图2,在一些实施例中,泄压机构200还可以包括第二金属片230,第二金属片230设置于胶膜210和外壳100之间,第二金属片230与外壳100焊接,第二金属片230设置有第二通孔231。
在一些实施例中,第二金属片230可以为铝、镍、不锈钢等材料制成,不易生锈,使用寿命较长。
在一些实施例中,第二金属片230与外壳100的焊接方式可以为激光焊接。
在一些实施例中,胶膜210能够被高温激活,以熔融后与第二金属片230贴合,待胶膜210冷却后,固定于第二金属片230上,能够起到密封第一通孔101和第二通孔231的作用,当胶膜210再次受热熔融或失粘后,至少部分脱离第二金属片230,以形成第一泄压通道。
通过设置第二金属片230以与外壳100焊接,能够使得泄压机构200与外壳100的连接更加稳定,密封效果更好。
由于第一通孔101复用注液孔,电化学装置10在注液完成后,可能在注液孔处存在电解液残留,电解液会对胶膜210的粘性造成影响,使得胶膜210与外壳100的贴合不牢固,因此通过设置第二金属片230以与外壳100焊接,能够进一步使得泄压机构200与外壳100的连接更加稳定,密封效果更好。
在一些实施例中,可以先将胶膜210分别与第一金属片220和第二金属片230贴合,以组成泄压机构200,然后再将泄压机构200与外壳100焊接连接,能够使得制备工艺更加简便,且泄压机构200能够适配多种尺寸的第一通孔101,泄压机构200的通用性较好。
在其他实施例中,也可以将第一金属片220、胶膜210、第二金属片230先进行堆叠,然后在第二金属片230与外壳100进行焊接时,使得焊接高温将胶膜210熔融,以同步实现胶膜210与第一金属片220、第二金属片230的贴合。
参见图2和图4,在一些实施例中,第二金属片230呈圆环形设置,第二金属片230的外径D2大于或等于第一通孔101的直径D1,第一金属片220的直径D4小于或等于第二金属片230的外径D2,第一金属片220的直径D4大于或等于第二金属片230的内径D3。
通过将第二金属片230设置成圆环形,使得第二金属片230能够形成第一泄压通道,使得泄压机构200的泄压效果较好。通过使得第二金属片230的外径D2大于或等于第一通孔101的直径D1,便于第二金属片230与外壳100焊接。通过使得第一金属片220的直径D4小于或等于第二金属片230的外径D2,能够在第一金属片220、胶膜210、第二金属片230与外壳100装配时,减小第一金属片220遮挡第二金属片230的可能性,便于第二金属片230在外壳100上的定位,使得第二金属片230覆盖第一通孔101,从而便于胶膜210、第一金属片220、第二金属片230与外壳100装配,且泄压机构200与外壳100的密封更好。通过使得第一金属片220的直径D4大于或等于第二金属片230的内径D3,使得第一金属片220能够覆盖第二通孔231,减小水汽经胶膜210、第二通孔231渗入外壳100内部的可能性,使得泄压机构200的密封效果更好。
在另一些实施例中,第二金属片230也可以呈椭圆环形、方环形等形状设置。
在一些实施例中,第一通孔101的直径为D1,第二金属片230的外径为D2,第二金属片230的内径为D3,满足0.2mm≤D1≤5mm,1mm≤D2≤6mm,0.1mm≤D3≤3mm。例如D1可以为0.2mm、3mm或5mm等,D2可以为1mm、4mm或6mm等,D3可以为0.1mm、1.2mm或3mm等。
其中,第二金属片230的内径D3即第二通孔231的直径。
通过将第一通孔101的直径D1设置在0.2mm至5mm,能够使得电化学装置10在热失控时,第一通孔101能够提供截面积较大的第一泄压通道,且无需较大尺寸的泄压机构200覆盖第一通孔101,便于泄压机构200的安装和节省泄压机构200的成本。通过将第二金属片230的外径D2设置在1mm至6mm,使得第二金属片230有足够的面积与外壳100贴合,能够便于第二金属片230与外壳100的焊接,且第二金属片230不会超出外壳100,成本较低。通过将第二金属片230的内径D3设置在0.1mm至3mm,使得通过第二通孔231形成第一泄压通道时,第二通孔231能够提供截面积较大的第一泄压通道,且无需较大尺寸的胶膜210和第一金属片220覆盖第二通孔,便于胶膜210和第一金属片220的安装,节省胶膜210和第一金属片220的成本。
在一些实施例中,第一通孔101的截面积为第一通孔101在其径向的平行平面上的截面的 面积。第二金属片230不超出外壳100是指第二金属片230在其径向上不超出外壳100的边缘。
在一些实施例中,第一通孔101的直径D1满足0.5mm≤D1≤3mm。例如D1可以为0.5mm、1.5mm或3mm等。通过将第一通孔101的直径D1设置在0.5mm至3mm,能够进一步使得电化学装置10在热失控时,第一通孔101能够提供截面积较大的第一泄压通道,且无需较大尺寸的泄压机构200覆盖第一通孔101,便于泄压机构200的安装和节省泄压机构200的成本。
在一些实施例中,第二金属片230的外径D2满足2mm≤D2≤5mm。例如D2可以为2mm、3mm或5mm等。通过将第二金属片230的外径D2设置在2mm至5mm,能够进一步使得第二金属片230有足够的面积与外壳100贴合,能够便于第二金属片230与外壳100的焊接,且第二金属片230不会超出外壳100,成本较低。
在一些实施例中,第二金属片230的内径D3满足0.3mm≤D3≤1.5mm。例如D3可以为0.3mm、1mm或1.5mm等。通过将第二金属片230的内径D3设置在0.3mm至1.5mm,能够进一步使得通过第二通孔231形成第一泄压通道时,第二通孔231能够提供截面积较大的第一泄压通道,且无需较大尺寸的胶膜210和第一金属片220覆盖第二通孔,便于胶膜210和第一金属片220的安装,节省胶膜210和第一金属片220的成本。
在一些实施例中,第一金属片220的厚度为H1,第二金属片230的厚度为H2,满足0.03mm≤H1≤1mm,0.03mm≤H2≤1mm。例如H1可以为0.03mm、0.5mm或1mm等,H2可以为0.03mm、0.4mm或1mm等。
通过将第一金属片220的厚度H1设置在0.03mm至1mm,将第二金属片230的厚度H2设置在0.03mm至1mm,使得第一金属片220和第二金属片230的密封效果更好,减小水汽渗入外壳100内部的可能性,并且能够使得泄压机构200的厚度较小,从而使得泄压机构200在电化学装置10的长度方向上占用的空间较小,电化学装置10的更多空间可以用于设置电极组件400,从而有利于提高电化学装置10的能量密度。
在一些实施例中,第一金属片220的厚度H1满足0.05mm≤H1≤0.15mm,第二金属片230的厚度H2满足0.05mm≤H2≤0.15mm。例如H1可以为0.05mm、0.1mm或0.15mm等,H2可以为0.05mm、0.11mm或0.15mm等。通过将第一金属片220的厚度H1设置在0.05mm至0.15mm,将第二金属片230的厚度H2设置在0.05mm至0.15mm,能够进一步使得第一金属片220和第二金属片230的密封效果更好,减小水汽渗入外壳100内部的可能性,并且能够使得泄压机构200的厚度较小,从而使得泄压机构200在电化学装置10的长度方向上占用的空间较小,电化学装置10的更多空间可以用于设置电极组件400,从而有利于提高电化学装置10的能量密度。
在一些实施例中,胶膜210的厚度为H3,满足0.05mm≤H3≤1mm。例如H3可以为0.05mm、0.4mm或1mm等。
通过将胶膜210的厚度H3设置在0.05mm至1mm,能够使得胶膜210不易破损,透水性较低,容易受高温熔融或失粘以形成第一泄压通道,使得泄压机构200的泄压灵敏度较高,泄压效果较好,并且在常温时与第一金属片220和第二金属片230的粘合力较强,对第一通孔101的密封效果较好。
在一些实施例中,胶膜210的厚度H3满足0.1mm≤H3≤0.3mm。例如H3可以为0.1mm、0.2mm或0.3mm等。通过将胶膜210的厚度H3设置在0.1mm至0.3mm,能够进一步使得胶膜210不易破损,透水性更低,容易受高温熔融或失粘以形成第一泄压通道,使得泄压机构200的泄压灵敏度较高,泄压效果较好,并且在常温时与第一金属片220和第二金属片230的粘合力较强,对第一通孔101的密封效果较好。
参见图6和图7,图6为本申请另一些实施例提供的电化学装置的立体结构示意图,图7为图6实施例提供的电化学装置的部分结构的剖视示意图。
在另一些实施例中,泄压机构200可以只包括胶膜210,胶膜210能够受热熔融或失粘以形成连通外壳100内部和外部的第一泄压通道,使得电化学装置10在温度较高时能够通过泄压机构200进行泄压,电化学装置10的泄压灵敏度和泄压的可靠性较高,能够减小电化学装置10热失控的概率。
参见图8和图9,图8为本申请另一些实施例提供的电化学装置的立体结构示意图,图9为图8实施例提供的电化学装置的部分结构的剖视示意图。
在另一些实施例中,泄压机构200可以只包括胶膜210和第一金属片220,胶膜210能够受热熔融或失粘以形成连通外壳100内部和外部的第一泄压通道,使得电化学装置10在温度较高 时能够通过泄压机构200进行泄压,电化学装置10的泄压灵敏度和泄压的可靠性较高,能够减小电化学装置10热失控的概率。第一金属片220能够减小胶膜210的渗水面积,使得密封效果更好,进而使得电化学装置10的使用寿命更长。
参见图2、图10和图11,图10为本申请一些实施例提供的电化学装置的胶膜的一个视角的结构示意图,图11为本申请一些实施例提供的电化学装置的胶膜的另一个视角的剖视结构示意图。
在一些实施例中,胶膜210包括第一胶层211、第二胶层212以及第三胶层213,第二胶层212、第一胶层211、第三胶层213依次层叠设置,第二胶层212位于第一胶层211背向外壳100的一侧,第一胶层211的熔点小于第二胶层212的熔点,第三胶层213位于第二胶层212和第一金属片220之间,第三胶层213的熔点小于第二胶层212的熔点。
在一些实施例中,第二胶层212、第一胶层211、第三胶层213沿胶膜210的厚度方向层叠设置。通过使得第一胶层211的熔点小于第二胶层212的熔点,第三胶层213的熔点小于第二胶层212的熔点,能够使得胶膜210被高温激活时,第一胶层211能够熔融以与外壳100贴合,第三胶层213能够熔融以与第一金属片220贴合,同时第二胶层212不会熔融,能够避免胶膜210过熔融而影响胶膜210的安装,还能够减少溢胶量。电化学装置10在热失控时,第一胶层211与外壳100之间、第三胶层213与第一金属片220之间能够分别形成两条第一泄压通道,相比只有一条第一泄压通道,此实施例中泄压机构200的泄压可靠性更高,能够减小第一泄压通道无法形成的概率,并且当两条第一泄压通道同时打开时,能够提高泄压机构200的泄压速度,因此胶膜210为三层结构能够提高电化学装置10的泄压灵敏性、泄压的可靠性,减小电化学装置10热失控的概率。
在一些实施例中,第一胶层211的熔点为T1,第二胶层212的熔点为T2,第三胶层213的熔点为T3,满足95℃≤T1≤135℃,140℃≤T2≤190℃,95℃≤T3≤135℃。例如T1可以为95℃、100℃或135℃等,T2可以为95℃、105℃或135℃等,T3可以为95℃、110℃或135℃等。
通过将第一胶层211的熔点T1设置在95℃至135℃,将第二胶层212的熔点T2设置在140℃至190℃,将第三胶层213的熔点T3设置在95℃至135℃,能够使得胶膜210对第一通孔101的密封可靠性较高,且第一胶层211能够先于第二胶层212熔融,便于在胶膜210被高温激活时安装于外壳100,第三胶层213能够先于第二胶层212熔融,便于在胶膜210被高温激活时安装于第一金属片220。电化学装置10在热失控时,第一胶层211能够比第二胶层212先熔融或失粘以形成第一泄压通道,第三胶层213能够比第二胶层212先熔融或失粘以形成第一泄压通道,使得电化学装置10的泄压灵敏性较高,且能够减少胶膜210的溢胶量。
在另一些实施例中,胶膜210可以为单层结构,胶膜210的熔点为T,满足95℃≤T≤135℃,例如T可以为95℃、120℃或135℃等。
通过将胶膜210的熔点T设置在95℃至135℃,能够使得胶膜210对第一通孔101的密封可靠性较高,且电化学装置10在热失控时,胶膜210能够熔融或失粘以形成第一泄压通道,使得电化学装置10的泄压灵敏性较高。
在另一些实施例中,胶膜210可以为双层结构,包括第一胶层211和第二胶层212,第一胶层211与第二胶层212层叠设置,第二胶层212位于第一胶层211背向外壳100的一侧,第一胶层211的熔点小于第二胶层212的熔点。
通过将胶膜210设置为双层结构,且胶膜210包括第一胶层211和第二胶层212,并且使得第一胶层211的熔点小于第二胶层212的熔点,能够使得胶膜210被高温激活时,第一胶层211能够熔融以与外壳100贴合,同时第二胶层212不会熔融,能够避免胶膜210过熔融而影响胶膜210的安装,还能够减少胶膜210的溢胶量。
在一些实施例中,第一胶层211的熔点为T1,第二胶层212的熔点为T2,满足95℃≤T1≤135℃,140℃≤T2≤190℃。例如T1可以为95℃、100℃或135℃等,T2可以为95℃、105℃或135℃等。
在一些实施例中,外壳100可以设置有凹槽(图中未示出),第一通孔101贯穿凹槽,泄压机构200容置于凹槽内。
通过在外壳100设置凹槽,并使得第一通孔101贯穿凹槽,泄压机构200容置于凹槽内,使得泄压机构200超出外壳的外表面的部分的厚度较小,从而能够减小泄压机构200与其他部件干涉而受损或脱离外壳100的可能性。
在一些实施例中,泄压机构200不超出外壳的外表面,能够进一步减小泄压机构200与其 他部件干涉而受损或脱离外壳100的可能性。
参见图1、图2、图12和图13,图12为本申请一些实施例提供的电化学装置的一个视角的结构示意图;图13为本申请一些实施例提供的电化学装置的另一个视角的剖视结构示意图。
在一些实施例中,外壳100包括壳体110和壳盖120,壳体110包括底壁111和围设于底壁111的多个侧壁,底壁111和多个侧壁共同围成具有开口的容纳空间,壳盖120封闭开口,侧壁为第一壁体,底壁111或壳盖120为所述第二壁体。
在一些实施例中,壳盖120呈板状设置,壳盖120封闭壳体110形成的开口。
在另一些实施例中,壳盖120也可以为一端开口的空心结构,壳盖120的开口侧盖合与壳体110的开口侧,以形成容纳空间。刻痕槽102可以设置于壳盖120与底壁111相对的壁体上。
在一些实施例中,壳体110和壳盖120可以为铝、镍、不锈钢等材料制成,使得外壳100觉有较高的受力性能,且不易生锈,使用寿命较长。
在一些实施例中,壳体110、壳盖120和第二金属片230可以为相同的金属材料制成,便于壳体110和壳盖120的焊接,便于壳体110和第二金属片230的焊接。
在一些实施例中,壳体110和壳盖120可以通过激光焊接的方式固定连接。
通过将第一通孔101设置于壳体110的侧壁,能够减小第一泄压通道被阻挡的可能,泄压机构200的泄压可靠性较高。通过将刻痕槽102设置于壳体110的底壁111或壳盖120,能够形成尺寸较大的第二泄压通道,便于外壳100内部的气体快速排出,泄压可靠性较高。
在一些实施例中,壳体110的侧壁上可以设置有多个第一通孔101,多个第一通孔101间隔设置。通过设置多个第一通孔101,能够进一步提高电化学装置10的泄压灵敏度和泄压的可靠性,还能够提高泄压的速度,从而进一步减小电化学装置10热失控的概率。
在一些实施例中,每个第一通孔101上可以设置有一个胶膜210,胶膜210覆盖第一通孔101,多个胶膜210的熔点可以不同,以在电化学装置10温度较高时自动调整泄压速度。例如,电化学装置10的温度达到熔点最低的一个胶膜210的熔点温度时,此胶膜210熔融或失粘并形成一个第一泄压通道,泄压速度较慢,而当电化学装置10的温度持续升高时,其他胶膜210依次熔融或失粘并形成第一泄压通道,泄压速度加快,即电化学装置10的温度越高,电化学装置10的泄压速度越快,能够进一步减小电化学装置10热失控的可能性。
在一些实施例中,底壁111和/或壳盖120上可以设置有多个刻痕槽102,多个刻痕槽102间隔设置。通过设置多个刻痕槽102,能够进一步提高电化学装置10的泄压灵敏度和泄压的可靠性,还能够提高泄压的速度,从而进一步减小电化学装置10热失控的概率。
例如,壳盖120上设置两个刻痕槽102,两个刻痕槽102分别设置于壳盖120靠近极柱300的两个顶角,且对称设置,能够使得外壳100内部的气体经两个刻痕槽102破裂形成的泄压口排出时,壳盖120受力更加均匀,不易产生较大的变形以挤压其他装置。
在一些实施例中,底壁111和壳盖120可以为电化学装置10的外表面的面积最大的两个表面,电化学装置10内部压力较大时,容易使得底壁111和壳盖120产生形变,因此将刻痕槽102设置于底壁111或壳盖120,刻痕槽102更容易在电化学装置10内部压力较大时破裂。并且通过泄压机构200形成第一泄压通道,通过刻痕槽102形成第二泄压通道,能够减少经第二泄压通道流出的气体,从而使得刻痕槽102所在的底壁111或壳盖120受到的压力更小,不易产生较大的变形,进而能够减小挤压其他装置的风险。
在一些实施例中,多个侧壁可以包括第一侧壁112、第二侧壁113、第三侧壁114以及第四侧壁115,第一侧壁112与第三侧壁114相对设置,第二侧壁113与第四侧壁115相对设置,第一侧壁112分别与第二侧壁113和第四侧壁115连接,第三侧壁114分别与第二侧壁113和第四侧壁115连接。电化学装置10还包括极柱300,极柱300和第一通孔101设置于同一个侧壁(例如第一侧壁112)。
在另一些实施例中,极柱300和第一通孔101也可以设置于不同的侧壁。例如极柱300设置于第一侧壁112,第一通孔101设置于第二侧壁113。
由于极柱300能够用于与电路板(图中未示出)进行连接,通过将极柱300和第一通孔101设置于不同的侧壁,能够使得泄压机构200形成第一泄压通道后,电化学装置10内部的电解液不易经第一泄压通道喷溅至电路板上,从而能够减小电解液造成电路板上的元器件短路的可能性。
在一些实施例中,极柱300和第一通孔101设置于不同的侧壁,且第一通孔101靠近极柱300设置,使得外壳100内部的气体能够经电极组件400和外壳100之间形成的间隔空间、泄压机 构200形成的第一泄压通道排出,泄压可靠性较高。
在一些实施例中,极柱300可以通过铆压、焊接等方式固定设置在外壳100的侧壁。
在电化学装置10设置极柱300的一侧,电极组件400和外壳100之间形成有间隔空间,通过将极柱300和第一通孔101设置于同一个侧壁,能够便于外壳100内部的气体经间隔空间、第一通孔101排出,泄压可靠性较高。并且由于电化学装置10被装入用电设备时,需要预留空间以便于极柱300与用电设备的其他装置电连接,因此将极柱300和第一通孔101设置于同一个侧壁,无需再另外为泄压机构200预留空间以实现泄压,并且第一侧壁112可以为壳体110的多个侧壁中面积最小的,需要预留的间隔空间也更小,能够进一步节省用电设备的空间,使得用电设备的结构更加紧凑。
在一些实施例中,刻痕槽102靠近外壳100的边角设置。
在一些实施例中,外壳100呈长方形设置,外壳100的边角即外壳100的四个顶角。
由于外壳100内部的压力增大时,刻痕槽102所在的底壁111或壳盖120变形,外壳100的边角为外壳100的应力集中区域,通过将刻痕槽102设置在外壳100的边角,在应力超过刻痕槽102所在的底壁111或壳盖120的材质的拉伸强度时,刻痕槽102容易破裂以形成泄压口,泄压可靠性更高。
在一些实施例中,刻痕槽102靠近外壳100设置有极柱300的一端。
在电化学装置10设置极柱的一侧,电极组件400和外壳100之间形成有间隔空间,通过使得刻痕槽102靠近外壳100设置有极柱300的一端,能够便于外壳100内部的气体经间隔空间、刻痕槽102破裂形成的泄压口排出,能够减小电极组件400堵塞刻痕槽102破裂形成的泄压口的可能性,泄压可靠性较高。并且无需在电极组件400与刻痕槽102所在的底壁111或壳盖120之间预留空间,以避免电极组件400堵塞刻痕槽102破裂形成的泄压口,从而能够增大电极组件400的体积,提高电化学装置10的能量密度。
在一些实施例中,刻痕槽102靠近外壳100上与极柱300距离最近的顶角,而第一通孔101位于极柱300所在的第一侧壁112上,且靠近外壳100的另一个顶角,泄压机构200与刻痕槽102分别位于外壳100沿宽度方向上的两端,具有一定距离,使得第一泄压通道和第二泄压通道都打开时,气体能够分别从外壳100沿宽度方向上的两端排出,而不会集中在外壳100的一个顶角处,能够减小外壳100的局部受力较大而产生变形的可能性。
在一些实施例中,刻痕槽102呈弧形设置,且朝向刻痕槽102所在的壳盖120或底壁111的中心弯曲。
在一些实施例中,刻痕槽102可以呈C字形或其他弧形设置。
相比将刻痕槽102设置成L形或V形等形状,蚀刻过程中有折弯,容易造成刻痕槽102蚀刻不连续或产生偏离等问题,通过将刻痕槽102设置成弧形,使得蚀刻刻痕槽102的过程更加连续,能够便于刻痕槽102的加工成型。由于电化学装置10的内部压力较大时,壳盖120或底壁111的中部受力较大,更容易产生形变,因此通过使得刻痕槽102朝向刻痕槽102所在的壳盖120或底壁111的中心弯曲,能够使得刻痕槽102更加靠近刻痕槽102所在的壳盖120或底壁111的中心,刻痕槽102更容易破裂并形成较大的泄压口,便于外壳100内部的气体快速排出,泄压可靠性较高。
一并参见图14,图14为图13所示的电化学装置的B处的局部放大结构示意图。
在一些实施例中,刻痕槽102的宽度向靠近外壳100内部的方向逐渐减小。
通过使得刻痕槽102的宽度向靠近外壳100内部的方向逐渐减小,能够减少刻痕槽102的加工成本,且由于刻痕槽102的体积越大,刻痕槽102所在的壳盖120或底壁111越容易受热变形,因此使得刻痕槽102的宽度向靠近外壳100内部的方向逐渐减小,还能够减少刻痕槽102所在的壳盖120或底壁111受热变形的可能性。
在一些实施例中,刻痕槽102的横截面可以呈倒梯形设置。
在另一些实施例中,刻痕槽102的横截面也可以呈V字形、U字形等形状设置。
其中,刻痕槽102的横截面为刻痕槽102在其延伸方向的垂直方向上的截面。
在一些实施例中,刻痕槽102的最大宽度为W,满足0.02mm≤W≤0.5mm。例如W可以为0.02mm、0.2mm或0.5mm等。
通过将刻痕槽102的最大宽度W设置在0.02mm至0.5mm,能够使得外壳100内部的压力较大时,刻痕槽102容易破裂,泄压可靠性较高,并且刻痕槽102的成本较低,刻痕槽102不易在 电化学装置10跌落或受外力作用时破裂。
在一些实施例中,0.05mm≤W≤0.2mm。例如W可以为0.05m、0.1mm或0.2mm等。
通过将刻痕槽102的最大宽度W设置在0.05mm至0.2mm,能够进一步使得外壳100内部的压力较大时,刻痕槽102容易破裂,泄压可靠性较高,并且刻痕槽102的成本较低,刻痕槽102不易在电化学装置10跌落或受外力作用时破裂。
在一些实施例中,0.06mm≤W≤0.18mm。例如W可以为0.06m、0.12mm或0.18mm等。
通过将刻痕槽102的最大宽度W设置在0.06mm至0.18mm,能够进一步使得外壳100内部的压力较大时,刻痕槽102容易破裂,泄压可靠性较高,并且刻痕槽102的成本较低,刻痕槽102不易在电化学装置10跌落或受外力作用时破裂;通过将本方案的热熔泄压(泄压机构200)与刻痕槽102集成于同一电化学装置10的外壳100,能够实现将刻痕槽102的最大宽度W设置在0.06至0.18mm。
在一些实施例中,第二壁体的厚度S2满足0.03mm≤S2≤0.3mm。例如S2可以为0.03mm、0.2mm或0.3mm等。
通过将第二壁体的厚度S2设置为0.03mm至0.3mm,能够使得第二壁体不易受力或受热变形,且第二壁体占用的空间较小,有利于提高电化学装置10的能量密度。
参见表1,表1为目前只设置刻痕槽的电化学装置的多个实施例和本申请中设置刻痕槽和泄压机构的电化学装置的多个实施例的热盒测试通过率及跌落测试通过率的对比。以刻痕槽102设置在壳盖120上为例进行实验。在表1中,S1为刻痕槽102的深度,S2为刻痕槽102所在的壳盖120的厚度,W为刻痕槽102的最大宽度。刻痕槽102的深度、壳盖120的厚度、刻痕槽102的最大宽度的单位都为mm。
热盒测试的方法如下:
(1)将电化学装置在23±2℃的环境下完全放电,再充满电。
(2)对电化学装置进行拍照,并记录电化学装置的OCV(Open Circuit Voltage,开路电压)和阻抗。
(3)将电化学装置放入温度为23℃的烘箱中,直至电化学装置的温度稳定。
(4)将感温线贴线在电化学装置的负极极耳附近。
(5)将OCV测量电缆与电化学装置连接,并关闭烘箱。
(6)使得烘箱温度从23±2℃的初始温度以5±2℃/min的速度升高,直到烘箱温度达到130±2℃,然后将烘箱温度保持在130±2℃,并保持60分钟。
(7)若电化学装置未产生爆炸、冒烟、起火等情况,则测试通过。
跌落测试的方法如下:
(1)将电化学装置在23±2℃的环境下充满电。
(2)对电化学装置进行拍照,并记录电化学装置的OCV(Open Circuit Voltage,开路电压)和阻抗。
(3)使得电化学装置的6个表面和4个顶角分别朝下,从1.5米的高度自由下落到混凝土表面上,其中高度是指电化学装置的最低点到混凝土表面的距离。
(4)将电化学装置静置1小时,观察电化学装置是否产生爆炸、冒烟、起火等情况。
(5)将电化学装置静置12小时后,检测电化学装置的OCV是否大于或等于跌落前OCV初始值的90%。
(6)若电化学装置未产生爆炸、冒烟、起火等情况,且电化学装置的OCV大于或等于跌落前OCV初始值的90%,则测试通过。
从表1的测试结果可以看出:
1、结合对比例1-4可以看出,电化学装置只设置刻痕槽进行泄压,刻痕槽的深度S1越大,热盒测试通过率越大,但是跌落测试通过率越小。
2、结合实施例1-3可以看出,电化学装置设置泄压机构和刻痕槽进行泄压,刻痕槽的最大宽度W为0.2mm,刻痕槽的深度S1为0.01-0.05mm时,刻痕槽的深度S1越大,热盒测试通过率越大,同时跌落测试通过率都较高。
3、结合实施例3-7可以看出,电化学装置设置泄压机构和刻痕槽进行泄压,刻痕槽的最大宽度W为0.2mm,刻痕槽的深度S1为0.05-0.07mm时,热盒测试通过率和跌落测试通过率都较高。
表1电化学装置的热盒测试通过率及跌落测试通过率。
4、结合实施例7-10可以看出,电化学装置设置泄压机构和刻痕槽进行泄压,刻痕槽的最大宽度W为0.2mm,刻痕槽的深度S1为0.07-0.095mm时,刻痕槽的深度S1越大,跌落测试通过率越小,同时热盒测试通过率较高。
5、结合对比例2和实施例1,热盒测试通过率都达到了70%,跌落测试通过率也相同,但是只设置刻痕槽进行泄压的电化学装置的刻痕槽深度为0.065mm,而本申请中设置泄压机构和刻痕槽的电化学装置的刻痕槽深度为0.01mm,因此本申请设置泄压机构和刻痕槽的电化学装置能够在降低刻痕槽的成本同时,达到相同的泄压效果。
6、结合对比例5-8可以看出,电化学装置只设置刻痕槽进行泄压,刻痕槽的最大宽度W越大,热盒测试通过率越大。
7、结合对比例6-10和实施例11,只设置刻痕槽进行泄压的电化学装置的刻痕槽的最大宽度为0.05-0.5mm,本申请中设置泄压机构和刻痕槽的电化学装置的刻痕槽的最大宽度为0.02mm,能够降低刻痕槽的成本,且热盒测试通过率提高,且跌落测试通过率未降低。
8、结合对比例1和实施例3,对比例2和实施例6,对比例3和实施例9,对比例5-10和
实施例11-16,相比只设置刻痕槽进行泄压的电化学装置,本申请中电化学装置设置泄压机构和刻痕槽进行泄压,能够提高热盒测试通过率,并且跌落测试通过率也未降低。
本申请还提供了一种用电设备,包括以上任一实施例提供的电化学装置10,电化学装置10用于提供电能。
用电设备可以是前述任一应用电化学装置10的装置或设备。
需要说明的是,在不冲突的情况下,本申请中的实施例及实施例中的特征可以相互结合。
以上仅为本申请的优选实施例而已,并不用于限制本申请,对于本领域的技术人员来说,本申请可以有各种更改和变化。凡在本申请的精神和原则之内,所作的任何修改、等同替换、改进等,均应包含在本申请的保护范围之内。

Claims (28)

  1. 一种电化学装置,其特征在于,包括:
    外壳,包括第一壁体和第二壁体,所述第一壁体设置有第一通孔;
    泄压机构,覆盖所述第一通孔,所述泄压机构包括胶膜,所述胶膜能够受热熔融或失粘以形成连通所述外壳内部和外部的第一泄压通道;
    所述第二壁体上设置有刻痕槽,所述刻痕槽能够在所述外壳的内部压力达到阈值时破裂,以形成连通所述外壳内部和外部的第二泄压通道;
    所述刻痕槽的深度为S1,所述第二壁体的厚度为S2,满足0.1*S2≤S1≤0.95*S2。
  2. 根据权利要求1所述的电化学装置,其特征在于,0.4*S2≤S1≤0.8*S2。
  3. 根据权利要求1所述的电化学装置,其特征在于,0.55*S2≤S1≤0.8*S2。
  4. 根据权利要求1所述的电化学装置,其特征在于,所述泄压机构还包括第一金属片,所述第一金属片设置于所述胶膜背向所述外壳的一侧。
  5. 根据权利要求4所述的电化学装置,其特征在于,所述第一金属片呈圆形设置,所述胶膜呈圆形或圆环形设置,所述第一通孔呈圆形设置,所述第一金属片的直径小于或等于所述胶膜的外径,所述第一金属片的直径大于或等于所述第一通孔的直径。
  6. 根据权利要求4所述的电化学装置,其特征在于,所述泄压机构还包括第二金属片,所述第二金属片设置于所述胶膜和所述外壳之间,所述第二金属片与所述外壳焊接,所述第二金属片设置有第二通孔。
  7. 根据权利要求6所述的电化学装置,其特征在于,所述第一金属片呈圆形设置,所述第一通孔呈圆形设置,所述第二金属片呈圆环形设置,所述第二金属片的外径大于或等于所述第一通孔的直径,所述第一金属片的直径小于或等于所述第二金属片的外径,所述第一金属片的直径大于或等于所述第二金属片的内径。
  8. 根据权利要求6所述的电化学装置,其特征在于,所述第一通孔呈圆形设置,所述第一通孔的直径为D1,所述第二金属片呈圆环形设置,所述第二金属片的外径为D2,所述第二金属片的内径为D3,满足0.2mm≤D1≤5mm,1mm≤D2≤6mm,0.1mm≤D3≤3mm。
  9. 根据权利要求6所述的电化学装置,其特征在于,所述第一金属片的厚度为H1,所述第二金属片的厚度为H2,满足0.03mm≤H1≤1mm,0.03mm≤H2≤1mm。
  10. 根据权利要求1所述的电化学装置,其特征在于,所述胶膜的熔点为T,满足95℃≤T≤135℃。
  11. 根据权利要求1所述的电化学装置,其特征在于,所述胶膜包括第一胶层和第二胶层,所述第一胶层与所述第二胶层层叠设置,所述第二胶层位于所述第一胶层背向所述外壳的一侧,所述第一胶层的熔点小于所述第二胶层的熔点。
  12. 根据权利要求11所述的电化学装置,其特征在于,所述第一胶层的熔点为T1,所述第二胶层的熔点为T2,满足95℃≤T1≤135℃,140℃≤T2≤190℃。
  13. 根据权利要求11所述的电化学装置,其特征在于,所述泄压机构还包括第一金属片,所述第一金属片设置于所述胶膜背向所述外壳的一侧,所述胶膜还包括第三胶层,所述第三胶层位于所述第二胶层和所述第一金属片之间,所述第三胶层的熔点小于所述第二胶层的熔点。
  14. 根据权利要求13所述的电化学装置,其特征在于,所述第三胶层的熔点为T3,满足95℃≤T3≤135℃。
  15. 根据权利要求1所述的电化学装置,其特征在于,所述外壳设置有凹槽,所述第一通孔贯穿所述凹槽,所述泄压机构容置于所述凹槽内。
  16. 根据权利要求1所述的电化学装置,其特征在于,所述第一通孔呈跑道形、长方形或椭圆形设置。
  17. 根据权利要求1所述的电化学装置,其特征在于,所述外壳包括壳体和壳盖,所述壳体包括底壁和围设于所述底壁的多个侧壁,所述底壁和多个所述侧壁共同围成具有开口的容纳空间,所述壳盖封闭所述开口,所述侧壁为所述第一壁体,所述底壁或所述壳盖为所述第二壁体。
  18. 根据权利要求17所述的电化学装置,其特征在于,所述电化学装置还包括极柱,所述极柱和所述第一通孔设置于同一个所述侧壁。
  19. 根据权利要求17所述的电化学装置,其特征在于,所述电化学装置还包括极柱,所述极柱和所述第一通孔设置于不同的所述侧壁。
  20. 根据权利要求17所述的电化学装置,其特征在于,所述刻痕槽靠近所述外壳的边角设置。
  21. 根据权利要求20所述的电化学装置,其特征在于,所述电化学装置还包括极柱,所述极柱设置于所述外壳,所述刻痕槽靠近所述外壳设置有所述极柱的一端。
  22. 根据权利要求17所述的电化学装置,其特征在于,所述刻痕槽呈弧形设置,且朝向所述刻痕槽所在的所述壳盖或所述底壁的中心弯曲。
  23. 根据权利要求1所述的电化学装置,其特征在于,所述刻痕槽的宽度向靠近所述外壳内部的方向逐渐减小。
  24. 根据权利要求1所述的电化学装置,其特征在于,所述刻痕槽的最大宽度为W,满足0.02mm≤W≤0.5mm。
  25. 根据权利要求23所述的电化学装置,其特征在于,0.05mm≤W≤0.2mm。
  26. 根据权利要求23所述的电化学装置,其特征在于,0.06mm≤W≤0.18mm。
  27. 根据权利要求1所述的电化学装置,其特征在于,所述第二壁体的厚度S2满足0.03mm≤S2≤0.3mm。
  28. 一种用电设备,其特征在于,包括如权利要求1至27任意一项所述的电化学装置,所述电化学装置用于提供电能。
PCT/CN2024/131037 2023-11-15 2024-11-08 电化学装置及用电设备 Pending WO2025103239A1 (zh)

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